Vulnerability-Lookup

GHSA-66M4-5JJR-2RG5

Vulnerability from github – Published: 2026-07-21 20:11 – Updated: 2026-07-21 20:11

Summary

Gitea: Webhooks created by a collaborator keep firing after their repo access is revoked → ongoing real-time exfiltration of private repo content

Details

Affected product

Gitea — services/repository/collaboration.go (DeleteCollaboration) + webhook delivery

Summary

When a collaborator with admin permission on a private repo creates a webhook, that webhook keeps firing after the collaborator's access is revoked. Gitea's revocation cleanup DeleteCollaboration removes the collaboration record, recalculates accesses, drops watches, and unassigns issues — but it does not remove or disable webhooks the user created, and webhook delivery never re-checks whether the creator still has repo access. The former collaborator therefore receives the full payload (issue/comment bodies, commit data) of all future repository events at their controlled endpoint, indefinitely and invisibly.

Affected code

services/repository/collaboration.go → DeleteCollaboration() — cleans watches/assignees only; no webhook cleanup.
Webhook delivery path — fires on repo events without re-validating the creator's current access.

Steps to reproduce

Using the provided reproduction materials: 1. Attacker (admin collaborator) creates a webhook → revoke access. 2. Control: GET /api/v1/repos/admin/wh-repo (attacker) → 404. 3. GET .../hooks → webhook still active=true. 4. Admin creates a new issue after revocation → the catcher receives action:"opened", issue.title:"CRITICAL SECRET: …", issue.body (sentinel private key), repository.private:true. (Runtime-confirmed on gitea/gitea:1.25.4. Catcher is an internal sentinel listener; the payload is a planted sentinel, not real data; nothing is sent to any external/metadata endpoint.)

Impact

Authenticated former admin-collaborator → ongoing real-time exfiltration of private content created after revocation; invisible to the owner; scope crosses from the application boundary to data the user should no longer access.

Suggested remediation

On revocation, delete/disable webhooks created by the removed collaborator (or hand them to the owner).
Re-validate the creator's current repo access before each webhook delivery.
At minimum, warn admins on revocation if the user created webhooks.

Credit

Reported as part of an incomplete-patch / authorization-residue measurement study (responsible disclosure).

Severity

6.8 (Medium)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "gitea.dev"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.27.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-58440"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-21T20:11:36Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Affected product\nGitea \u2014 `services/repository/collaboration.go` (`DeleteCollaboration`) + webhook delivery\n\n## Summary\nWhen a collaborator with admin permission on a private repo creates a webhook, that webhook keeps firing\nafter the collaborator\u0027s access is revoked. Gitea\u0027s revocation cleanup `DeleteCollaboration` removes the\ncollaboration record, recalculates accesses, drops watches, and unassigns issues \u2014 but it does **not**\nremove or disable webhooks the user created, and webhook delivery never re-checks whether the creator still\nhas repo access. The former collaborator therefore receives the full payload (issue/comment bodies, commit\ndata) of all future repository events at their controlled endpoint, indefinitely and invisibly.\n\n## Affected code\n- `services/repository/collaboration.go` \u2192 `DeleteCollaboration()` \u2014 cleans watches/assignees only; no\n  webhook cleanup.\n- Webhook delivery path \u2014 fires on repo events without re-validating the creator\u0027s current access.\n\n## Steps to reproduce\nUsing the provided reproduction materials:\n1. Attacker (admin collaborator) creates a webhook \u2192 revoke access.\n2. Control: `GET /api/v1/repos/admin/wh-repo` (attacker) \u2192 **404**.\n3. `GET .../hooks` \u2192 webhook still `active=true`.\n4. Admin creates a new issue **after** revocation \u2192 the catcher receives `action:\"opened\"`,\n   `issue.title:\"CRITICAL SECRET: \u2026\"`, `issue.body` (sentinel private key), `repository.private:true`.\n(Runtime-confirmed on `gitea/gitea:1.25.4`. Catcher is an internal sentinel listener; the payload is a\nplanted sentinel, not real data; nothing is sent to any external/metadata endpoint.)\n\n## Impact\nAuthenticated former admin-collaborator \u2192 ongoing real-time exfiltration of private content created after\nrevocation; invisible to the owner; scope crosses from the application boundary to data the user should no\nlonger access.\n\n## Suggested remediation\n1. On revocation, delete/disable webhooks created by the removed collaborator (or hand them to the owner).\n2. Re-validate the creator\u0027s current repo access before each webhook delivery.\n3. At minimum, warn admins on revocation if the user created webhooks.\n\n## Credit\nReported as part of an incomplete-patch / authorization-residue measurement study (responsible disclosure).",
  "id": "GHSA-66m4-5jjr-2rg5",
  "modified": "2026-07-21T20:11:36Z",
  "published": "2026-07-21T20:11:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-66m4-5jjr-2rg5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/pull/38406"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/pull/38426"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/commit/de4b8277e9cb576f2315fb03b5ab6478b42a1d31"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/commit/f69e15afe7496cc62e96dab244629c69eb31a7bf"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/go-gitea/gitea"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/releases/tag/v1.27.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Gitea: Webhooks created by a collaborator keep firing after their repo access is revoked \u2192 ongoing real-time exfiltration of private repo content"
}

CVE-2026-58440 (GCVE-0-2026-58440)

Vulnerability from cvelistv5 – Published: 2026-08-13 16:44 – Updated: 2026-08-14 19:59

Title

Webhooks created by a collaborator keep firing after their repo access is revoked → ongoing real-time exfiltration of private repo content (incomplete revocation cleanup in `DeleteCollaboration`)

Summary

Webhooks created by a collaborator keep firing after their repo access is revoked → ongoing real-time exfiltration of private repo content (incomplete revocation cleanup in `DeleteCollaboration`)

Severity

6.8 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-14 19:58 UTC

CWE

CWE-284

Assigner

Gitea mitre root

References

3 references

URL	Tags
https://github.com/go-gitea/gitea/security/adviso…	vendor-advisory
https://github.com/go-gitea/gitea/releases/tag/v1.27.0	release-notes
https://blog.gitea.com/gitea-1.27.0-is-released/	release-notes

Impacted products

1 product

Vendor	Product	Version
Gitea	Gitea Open Source Git Server	Affected: 0 , ≤ 1.26.4 (semver)

Credits

sec-reex

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 6.8,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "HIGH",
              "scope": "CHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-58440",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-14T19:58:47.519084Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-14T19:59:35.049Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-66m4-5jjr-2rg5"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Gitea Open Source Git Server",
          "vendor": "Gitea",
          "versions": [
            {
              "lessThanOrEqual": "1.26.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "sec-reex"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Webhooks created by a collaborator keep firing after their repo access is revoked \u2192 ongoing real-time exfiltration of private repo content (incomplete revocation cleanup in `DeleteCollaboration`)"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-284",
              "description": "CWE-284",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-13T16:44:54.496Z",
        "orgId": "88ee5874-cf24-4952-aea0-31affedb7ff2",
        "shortName": "Gitea"
      },
      "references": [
        {
          "name": "GitHub Security Advisory",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-66m4-5jjr-2rg5"
        },
        {
          "name": "Gitea v1.27.0 Release",
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/go-gitea/gitea/releases/tag/v1.27.0"
        },
        {
          "name": "Gitea v1.27.0 Release Blog Post",
          "tags": [
            "release-notes"
          ],
          "url": "https://blog.gitea.com/gitea-1.27.0-is-released/"
        }
      ],
      "title": "Webhooks created by a collaborator keep firing after their repo access is revoked \u2192 ongoing real-time exfiltration of private repo content (incomplete revocation cleanup in `DeleteCollaboration`)",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "88ee5874-cf24-4952-aea0-31affedb7ff2",
    "assignerShortName": "Gitea",
    "cveId": "CVE-2026-58440",
    "datePublished": "2026-08-13T16:44:54.496Z",
    "dateReserved": "2026-06-30T18:57:20.616Z",
    "dateUpdated": "2026-08-14T19:59:35.049Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-66M4-5JJR-2RG5

Affected product

Summary

Affected code

Steps to reproduce

Impact

Suggested remediation

Credit

CVE-2026-58440 (GCVE-0-2026-58440)

Tags

Sightings

Nomenclature

Related by attack behaviour