GHSA-4c8f-3m6h-m56r CVE-2026-27657 GO-2026-6335

Gitea primary email ownership bypass allows cross-user email changes

High Go

Severity: 7.5 / 10; High · CVSS 3.1
Exploit chance (EPSS): 0.45%; Chance of exploitation in the next 30 days. Higher than 39.20% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-639 Authorization Bypass Through User-Controlled Key
Fix: 1.25.5; Upgrade code.gitea.io/gitea to this version or later

Description

Gitea versions before 1.25.5 allow a user to change another user's primary email address.

Affected versions

Go

Package	Vulnerable	Fixed in
code.gitea.io/gitea	`< 1.25.5`	`1.25.5`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

code.gitea.io/gitea Go → `1.25.5`

go

go get code.gitea.io/gitea@v1.25.5 && go mod tidy

Severity breakdown

CVSS 3.1 7.5

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

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Weakness

CWE-639: Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

How to prevent it

Architecture and Design: For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design, Implementation: Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design: Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.

References

Advisories

Packages

github.com/go-gitea/gitea

Timeline

Jul 3, 2026 Published
Oct 25, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-rcr6-4jqh-j84m Gitea: Remote Code Execution via diffpatch Git Hook Installation	Critical Known exploited	Also affects code.gitea.io/gitea
GHSA-fq2p-5p22-8g6j Gitea: Public-Only Personal access tokens scope bypass in Organization and Permission Endpoints	Medium	Also affects code.gitea.io/gitea
GHSA-2wm4-vwp6-v7xc Gitea: SSRF via Migration Asset Downloads Bypasses hostmatcher — Reads Internal Files and Cloud Metadata	High	Also affects code.gitea.io/gitea
GHSA-3r5c-2xxx-h872 Gitea: Webhook Authorization Header Returned in Plaintext via API	Low	Also affects code.gitea.io/gitea
GHSA-frpw-3h2q-4jj6 Gitea: Cross-Repo Information Disclosure via Org-Level Actions Run/Job APIs	Medium	Also affects code.gitea.io/gitea
GHSA-q423-49rw-g9mh Gitea: GHSA-8fwc-qjw5-rvgp ClearRepoWatches fix not applied to API EditRepo path — sister code path retains stale watches on public->private	Medium	Also affects code.gitea.io/gitea
GHSA-2fcr-jfvc-vgg2 Gitea: Two SSRF findings	High	Also affects code.gitea.io/gitea
GHSA-fw57-jgch-pgf3 Gitea: ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests	High	Also affects code.gitea.io/gitea

Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor