CVE-2026-104976

Published Oct 5, 2026 Modified Oct 6, 2026 CWE-918

Description

Plane is an open-source project management tool. Prior to 1.4.0, Plane validates GITEA_HOST only for its URL scheme and does not reject hosts that resolve to private or internal IP addresses. The four outbound requests in the Gitea OAuth flow are derived from this unvalidated host and do not call validate_url(). In addition, avatar_url is taken from the Gitea user's profile, where users can configure external avatar URLs. After an administrator enables Gitea OAuth for a legitimate instance, a Gitea user can set an internal URL as the profile avatar and log in through Gitea, causing Plane to fetch the internal target without validation. This issue is fixed in 1.4.0.

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EPSS — Exploit Prediction

0.0025
Probability of exploitation
0.16%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-918 Server-Side Request Forgery (SSRF)

References

Frequently Asked Questions

What is CVE-2026-104976? +
Plane is an open-source project management tool. Prior to 1.4.0, Plane validates GITEA_HOST only for its URL scheme and does not reject hosts that resolve to private or internal IP addresses. The four outbound requests in the Gitea OAuth flow are derived from this unvalidated host and do not call validate_url(). In addition, avatar_url is taken from the Gitea user's profile, where users can configure external avatar URLs. After an administrator enables Gitea OAuth for a legitimate instance, a Gitea user can set an internal URL as the profile avatar and log in through Gitea, causing Plane to fetch the internal target without validation. This issue is fixed in 1.4.0.
How do I check if I'm vulnerable to CVE-2026-104976? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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