GHSA-CRC3-H8V6-QH57
Vulnerability from github – Published: 2026-05-19 19:37 – Updated: 2026-05-19 19:37Summary
A security vulnerability has been identified in GitHub CLI that could allow terminal escape sequence injection when users view GitHub Actions workflow logs using gh run view --log or gh run view --log-failed.
Details
The vulnerability stems from the way GitHub CLI handles raw Actions log output. The gh run view --log and gh run view --log-failed commands stream workflow log lines to stdout or the configured pager without sanitizing terminal control sequences. An attacker who can influence GitHub Actions log content, for example via a PR triggered workflow, can embed escape sequences that are replayed in the user's terminal when they inspect the run.
Depending on the victim's terminal emulator, injected sequences could change the window title, manipulate on screen content, or in some terminal emulators (such as screen) potentially execute arbitrary commands.
In 2.92.0, GitHub CLI sanitizes terminal control sequences in Actions log output before writing to the terminal.
PoC
Create a workflow that emits terminal escape sequences in its log output:
name: Escape Sequence PoC
on:
workflow_dispatch:
jobs:
emit-escape-sequences:
runs-on: ubuntu-latest
steps:
- name: Emit terminal escape sequences
run: |
# OSC title set
printf 'ESCAPE_MARKER_START \033]0;HIJACKED_TITLE\007 ESCAPE_MARKER_END\n'
# CSI color
printf 'ESCAPE_MARKER_START \033[31mRED_TEXT\033[0m ESCAPE_MARKER_END\n'
# Screen title set (enables command execution in screen terminal)
printf 'ESCAPE_MARKER_START \033k;malicious command;\033\\ ESCAPE_MARKER_END\n'
Then trigger the workflow and view its logs:
gh workflow run 'Escape Sequence PoC'
gh run view <run_id> --log
On vulnerable versions, the raw ESC bytes (0x1b) are passed through to the terminal unsanitized. On 2.92.0 and later, escape sequences are stripped and only the safe visible text is displayed.
Impact
An attacker who can control GitHub Actions workflow output can inject terminal escape sequences into a maintainer's terminal session when they inspect the run with gh run view --log or gh run view --log-failed. The practical impact depends on the victim's terminal emulator.
Remediation and Mitigation
- Upgrade
ghto2.92.0 - Pipe log output through a sanitizer (e.g.,
gh run view --log | cat -v) as a workaround on older versions - Exercise caution when viewing logs from untrusted workflow runs
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/cli/cli/v2"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.92.0"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Go",
"name": "github.com/cli/cli"
},
"ranges": [
{
"events": [
{
"introduced": "1.6.0"
},
{
"last_affected": "1.14.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-45803"
],
"database_specific": {
"cwe_ids": [
"CWE-150"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-19T19:37:01Z",
"nvd_published_at": "2026-05-15T16:16:15Z",
"severity": "LOW"
},
"details": "### Summary\n\nA security vulnerability has been identified in GitHub CLI that could allow terminal escape sequence injection when users view GitHub Actions workflow logs using `gh run view --log` or `gh run view --log-failed`.\n\n### Details\n\nThe vulnerability stems from the way GitHub CLI handles raw Actions log output. The `gh run view --log` and `gh run view --log-failed` commands stream workflow log lines to stdout or the configured pager without sanitizing terminal control sequences. An attacker who can influence GitHub Actions log content, for example via a PR triggered workflow, can embed escape sequences that are replayed in the user\u0027s terminal when they inspect the run.\n\nDepending on the victim\u0027s terminal emulator, injected sequences could change the window title, manipulate on screen content, or in some terminal emulators (such as `screen`) potentially execute arbitrary commands.\n\nIn `2.92.0`, GitHub CLI sanitizes terminal control sequences in Actions log output before writing to the terminal.\n\n### PoC\n\nCreate a workflow that emits terminal escape sequences in its log output:\n\n```yaml\nname: Escape Sequence PoC\n\non:\n workflow_dispatch:\n\njobs:\n emit-escape-sequences:\n runs-on: ubuntu-latest\n steps:\n - name: Emit terminal escape sequences\n run: |\n # OSC title set\n printf \u0027ESCAPE_MARKER_START \\033]0;HIJACKED_TITLE\\007 ESCAPE_MARKER_END\\n\u0027\n # CSI color\n printf \u0027ESCAPE_MARKER_START \\033[31mRED_TEXT\\033[0m ESCAPE_MARKER_END\\n\u0027\n # Screen title set (enables command execution in screen terminal)\n printf \u0027ESCAPE_MARKER_START \\033k;malicious command;\\033\\\\ ESCAPE_MARKER_END\\n\u0027\n```\n\nThen trigger the workflow and view its logs:\n\n```bash\ngh workflow run \u0027Escape Sequence PoC\u0027\ngh run view \u003crun_id\u003e --log\n```\n\nOn vulnerable versions, the raw ESC bytes (0x1b) are passed through to the terminal unsanitized. On `2.92.0` and later, escape sequences are stripped and only the safe visible text is displayed.\n\n### Impact\n\nAn attacker who can control GitHub Actions workflow output can inject terminal escape sequences into a maintainer\u0027s terminal session when they inspect the run with `gh run view --log` or `gh run view --log-failed`. The practical impact depends on the victim\u0027s terminal emulator.\n\n### Remediation and Mitigation\n\n1. Upgrade `gh` to `2.92.0`\n2. Pipe log output through a sanitizer (e.g., `gh run view --log | cat -v`) as a workaround on older versions\n3. Exercise caution when viewing logs from untrusted workflow runs",
"id": "GHSA-crc3-h8v6-qh57",
"modified": "2026-05-19T19:37:01Z",
"published": "2026-05-19T19:37:01Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/cli/cli/security/advisories/GHSA-crc3-h8v6-qh57"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45803"
},
{
"type": "PACKAGE",
"url": "https://github.com/cli/cli"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "GitHub CLI: GitHub Actions log output in `gh run view` allows terminal escape sequence injection"
}
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.