CVE-2026-27780
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedGitea 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn Gitea before version 1.26.0, the pre-receive hook input processing uses bufio.Scanner which has a default token size limit (64KB). When oversized input exceeds this limit, the Scanner returns an error, but the code does not fail closed—meaning it continues processing instead of rejecting the input, allowing the oversized payload to bypass branch protection checks.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine installed Gitea versionRun `gitea --version` from the command line, or log into the Gitea web admin panel and navigate to the Site Administration dashboard to view the version number.Affected if The version shown is earlier than 1.26.0 (for example, 1.25.x, 1.24.x, etc.).
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Identify if pre-receive hooks are in useIn the Gitea web UI, go to a repository settings page and examine the Branch Protection rules. Look for any protection rules that reference or enable pre-receive hooks (often labeled as 'pre-receive hook' or shown as a hook requirement before pushing).Affected if At least one branch protection rule has a pre-receive hook requirement enabled, meaning the vulnerability could be triggered by an oversized hook payload.
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ConfirmScanner behavior contextThis vulnerability applies specifically when the Gitea server processes pre-receive hook inputs. The flaw exists in the bufio.Scanner token handling within the hook processing code path.Affected if You are running a Gitea version below 1.26.0 AND you have branch protection rules that rely on pre-receive hooks, allowing the 64KB token limit to be bypassed when exceeded.
You are affected if your Gitea installation version is below 1.26.0 and you have branch protection rules that use pre-receive hooks, because oversized hook inputs can bypass those protection checks.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Gitea to version 1.26.0 or later, which implements proper fail-closed behavior on bufio.Scanner errors during pre-receive hook processing.
1.26.0
- Upgrade Gitea to version 1.26.0 or later to remediate this vulnerability
- Verify the upgrade by checking the Gitea administration panel or running `gitea --version`
- Review the release notes for 1.26.0 to understand any configuration or feature changes
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing8.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-27780 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-27780 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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