Executive brief
Gogs is an open-source self-hosted Git service used by teams to manage source code. A vulnerability in how the system handles issue tracking patterns allows a user with repository access to crash the page rendering engine. This results in a denial-of-service where any page referencing an issue (such as commit logs or pull requests) becomes inaccessible to all users of that repository.
Technical details
A denial-of-service vulnerability exists in Gogs due to improper handling of template strings in the issue index pattern rendering logic. In `internal/markup/markup.go`, the `RenderIssueIndexPattern` function utilizes `com.Expand` to process patterns. If a configured pattern contains an opening brace '{' without a corresponding closing brace '}', `strings.Index` returns -1, leading to an out-of-bounds slice operation (`template[:-1]`) that triggers a Go panic. An attacker with repository-level privileges can configure a malicious pattern, causing any page containing an issue reference (e.g., #1) to fail to load. This issue is resolved in version 0.14.3.
Affected products
- Gogs Gogs < 0.14.3
Timeline
- 2026-06-19: advisory: GitHub Security Advisory published
- 2026-06-24: disclosed: CVE published to NVD