Gogs: Open Redirect in /redirect endpoint via backslash bypass in `IsSameSite`

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

14 Oct 2026 18:49:19 UTC

Source modified

20 Oct 2026 01:58:51 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

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CVSS 4.0 · 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N