CVE-2026-82402: Gogs: Open Redirect in /redirect endpoint via backslash bypass in `IsSameSite`
Gogs is an open source self-hosted Git service. Prior to 0.15.0+dev, an unauthenticated attacker can provide a backslash-containing target to the /redirect endpoint, and similar post-action redirect flows are also affected. internal/urlx/urlx.go IsSameSite validates a normalized form of the target while cmd/gogs/internal/web/web.go getRedirect and other callers use the original value in the Location response. This backslash normalization mismatch lets browsers interpret the Location value as a scheme-relative external URL, allowing links on a trusted Gogs domain to redirect victims to attacker-controlled content for phishing. This vulnerability is fixed in 0.15.0+dev.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Gogsto a version that resolves this vulnerability.Fixed in 0.15.0+dev
Event History
Frequently Asked Questions
Who can exploit this issue?
An unauthenticated attacker can exploit the affected redirect endpoint and similar post-action redirect flows by supplying a target containing backslashes. Exploitation does not require an account on the Gogs instance.
What is the practical impact of exploitation?
Attackers can create links on a trusted Gogs domain that browsers interpret as redirects to attacker-controlled external content. This can support phishing by making the initial link appear to point to a legitimate Gogs instance.
Which versions are affected and what version fixes it?
Gogs versions prior to 0.15.0+dev are affected. The issue is fixed in 0.15.0+dev.
How can I identify potentially affected redirect handling?
Review requests to the /redirect endpoint and similar post-action flows for redirect target values containing backslashes. Those values may pass same-site validation but be returned in a Location header that browsers interpret as an external scheme-relative URL.