Gitea fork workflow approval bypass through concurrency cancellation
CVSS score
8.1
EPSS probability
—
Risk score
0.8
Published
4 h ago
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Vulnerability description
DayBreach CVE AI Research
CVE-2026-66877 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.
Gitea enforces first-time fork contributor approval by blocking jobs, but some job transition and dispatch paths do not re-check the run's approval requirement. A separate run sharing a job-level concurrency group can cancel a pending job and cause its blocked sibling jobs to be re-emitted and dispatched without approval. This allows unreviewed workflow code to execute on self-hosted runners; fork secrets remain withheld and the run token remains read-only.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-66877 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | gitea | gitea | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 8.1 | CVSS V3_1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | CVE ADP |
| 8.1 | CVSS V31 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-66877 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-66877 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
Similar Vulnerabilities
Code injection in Gitea
Gitea Runner host isolation bypass through container options
Gitea Org-mode file disclosure and code execution
Gitea fork workflow approval bypass through review events
Gitea private comparison disclosure with public-only tokens
Gitea required Actions check bypass through skipped workflows
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