CVE-2026-27780: Code.gitea.io/gitea Gitea Pre-receive Hook Scanner Errors Vulnerability

CRITICAL
Advisory Identifier: GHSA-vhq7-fwwh-7hjf
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CVSS 9.8
CWE-863
Published
Advisory Summary

CVE-2026-27780 is a CRITICAL (CVSS 9.8) gitea pre-receive hook scanner errors vulnerability (CWE-863: Incorrect Authorization) affecting Code.gitea.io/gitea libraries in the Go ecosystem. The issue involves gitea pre-receive hook scanner errors allow branch-protection bypass. Remediation is available by upgrading affected packages to version 1.26.0.

CVE-2026-27780 at a Glance

CVE Identifier CVE-2026-27780
GHSA Identifier GHSA-vhq7-fwwh-7hjf
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-863: Incorrect Authorization
Affected Product Code.gitea.io/gitea
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-27780

To remediate this vulnerability, upgrade all affected Code.gitea.io/gitea dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

code.gitea.io/gitea fixed: 1.26.0 
Upgrade code.gitea.io/gitea to 1.26.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for code.gitea.io/gitea

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-27780, inspect your project dependencies for Code.gitea.io/gitea:

inspect dependencies for code.gitea.io/gitea

Analyze the terminal output to locate any version of Code.gitea.io/gitea in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.26.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Code.gitea.io/gitea, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-27780 Affected Code.gitea.io/gitea Versions

1 component(s)
Fixed Versions:
1.26.0
Product / Package Ecosystem Affected Versions Fixed Version
code.gitea.io/gitea
golang/code.gitea.io/gitea
Go
< 1.26.0
1.26.0

References

NVD — CVE-2026-27780 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27780
Code.gitea.io/gitea Source Repository REPOSITORY
https://github.com/go-gitea/gitea/pull/36963
Security Fix Commit FIX COMMIT
https://github.com/go-gitea/gitea/commit/c453d09c36fad094405314dba2f370434b200711
blog.gitea.com/release-of-1.26.0 WEB
https://blog.gitea.com/release-of-1.26.0
Code.gitea.io/gitea Source Repository REPOSITORY
https://github.com/go-gitea/gitea
Code.gitea.io/gitea Release RELEASE
https://github.com/go-gitea/gitea/releases/tag/v1.26.0

Frequently Asked Questions

What is CVE-2026-27780?
CVE-2026-27780 is a security vulnerability in Code.gitea.io/gitea involving Gitea pre-receive hook scanner errors allow branch-protection bypass under CWE-863: Incorrect Authorization.
Which Code.gitea.io/gitea versions are affected?
Affected versions include releases prior to 1.26.0 across affected packages: code.gitea.io/gitea.
What version fixes CVE-2026-27780?
Upgrading to 1.26.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is code.gitea.io/gitea affected?
Yes, code.gitea.io/gitea is affected in releases prior to 1.26.0. Upgrade your dependency to 1.26.0 or later.
What is the CVSS score of CVE-2026-27780?
CVE-2026-27780 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-27780?
CVE-2026-27780 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check Go dependencies for CVE-2026-27780?
Run the dependency tree command: 'inspect dependencies for code.gitea.io/gitea'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vhq7-fwwh-7hjf",
  "modified" : "2026-09-01T18:55:25Z",
  "published" : "2026-07-03T21:31:38Z",
  "aliases" : [ "CVE-2026-27780" ],
  "summary" : "Gitea pre-receive hook scanner errors allow branch-protection bypass",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "code.gitea.io/gitea"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.26.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-27780"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/pull/36963"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/commit/c453d09c36fad094405314dba2f370434b200711"
  }, {
    "type" : "WEB",
    "url" : "https://blog.gitea.com/release-of-1.26.0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/go-gitea/gitea"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/releases/tag/v1.26.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-01T18:55:25Z",
    "nvd_published_at" : "2026-07-03T21:16:59Z"
  }
}