CVE-2026-78433

Gitea's web attachment handler skips its cross-repository ownership check for attachments created before 16 January 2026 and checks permissions against the repository named in the request URL instead. An unauthenticated attacker who knows a private attachment's UUID can request it through a public repository's attachment path and retrieve its contents. This can expose issue and pull request attachments or release assets; the random attachment UUID must already be known to the attacker.

• https://blog.gitea.com/release-of-1.27.3/
• https://github.com/go-gitea/gitea/pull/39048
• https://github.com/go-gitea/gitea/pull/39077
• https://github.com/go-gitea/gitea/releases/tag/v1.27.3
• https://github.com/go-gitea/gitea/security/advisories/GHSA-frpv-2xgv-wxpq