CVE & CISA-KEV Catalog

CVE-2026-104976

HIGH
8.7
CVSS v4
NVD

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.

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

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CVSS v4 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone

Impact

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploit Intelligence

0.25%probability of exploitation in 30 days
15thpercentile

Low risk: more likely to be exploited than 15% of all known CVEs.

References

Related Vulnerabilities

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2024-21893High8.2100%KEV + Ransom-
CVE-2021-40438Critical9.0100%KEV + RansomFix
CVE-2021-34473Critical9.1100%KEV + RansomFix
CVE-2021-21985Critical9.8100%KEV + RansomFix
CVE-2021-26855Critical9.1100%KEV + RansomFix
CVE-2022-41040High8.8100%KEV + RansomFix

Common questions

How do I fix CVE-2026-104976?

No published fix for CVE-2026-104976 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

Is CVE-2026-104976 being actively exploited?

Not that we know of. CVE-2026-104976 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.25% is the estimated probability that it will be exploited in the next 30 days. That is higher than 15% of all scored CVEs.

How severe is CVE-2026-104976?

CVE-2026-104976 has a CVSS v4 base score of 8.7, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-10-06.