CVE-2026-52802 is a medium-severity (CVSS 5.4) Open Redirect vulnerability in gogs.io/gogs. A fix is available for gogs.io/gogs — see the affected versions and patch details below.
Gogs: Open Redirect via redirect_to in Gogs
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-52802.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
gogs.io/gogsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
An open redirect vulnerability exists in Gogs where attacker-controlled redirect_to parameters can bypass validation, allowing redirection to arbitrary external sites.
Details
All redirects in Gogs that are validated via the IsSameSite function are vulnerable:
func IsSameSite(url string) bool {
return len(url) >= 2 && url[0] == '/' && url[1] != '/' && url[1] != '\\'
}
The function only inspects the first two characters of the URL string. This check fails to account for directory traversal sequences followed by backslashes. For example:
/a/../\example.com
The IsSameSite function checks the input supplied to the redirect_to query parameter value /a/../\example.com and considers it valid.
Because web browsers normalize backslashes \ to forward slashes /, the normalized URL becomes //example.com.
The normalized URL becomes:
//example.com
Resulting in a cross-origin redirect.
This affects all endpoints using the redirect_to query parameter, including login and other post-action flows.
PoC
- An attacker can provide a user with a link to login to Gogs with a
redirect_toquery parameter that redirects a user to a site the attacker wants them to visit:
http://192.168.236.132:3000/user/login?redirect_to=/a/../\example.com
- After the user successfully logs in, they would be redirected to the site an attacker wants them to visit:
Impact
- Phishing: Attackers can use trusted domain links to redirect victims to credential-harvesting pages
- OAuth/SSO Token Theft: In authentication flows, authorization codes or tokens may leak via redirect
- Referer Leakage: Sensitive URL parameters may be exposed to attacker domains via the Referer header
- Cache Poisoning: In deployments with shared caches, malicious redirects may be cached and served to other users
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | gogs.io/gogs | all versions | 0.14.3go get gogs.io/gogs@v0.14.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gogs.io/gogs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gogs.io/gogs to 0.14.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52802 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2026-52802 in your dependencies?
Find it across Go, including transitive dependencies.