CVE-2026-27780 is a critical-severity (CVSS 9.8) CWE-863 vulnerability in code.gitea.io/gitea. A fix is available for code.gitea.io/gitea — see the affected versions and patch details below.
Gitea pre-receive hook can miss branch-protection checks after scanner errors
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27780.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-27780 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,993 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
code.gitea.io/giteaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Gitea versions before 1.26.0 do not fail closed on bufio.Scanner errors while processing pre-receive hook input, allowing oversized input to bypass branch-protection checks.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | code.gitea.io/gitea | all versions | 1.26.0go get code.gitea.io/gitea@v1.26.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code.gitea.io/gitea, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update code.gitea.io/gitea to 1.26.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27780 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2026-27780 in your dependencies?
Find it across Go, including transitive dependencies.