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

> An attacker can exploit unvalidated Gitea OAuth host and avatar URLs to force the server to make requests to internal network resources.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-hx79-5pj5-qh42

## What is CVE-2026-104976?

CVE-2026-104976 is a high-severity server-side request forgery vulnerability in makeplane plane, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-104976?


## How do I fix CVE-2026-104976?

No fix has been published for CVE-2026-104976 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104976 being exploited?

There is no known exploitation of CVE-2026-104976 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104976 and fix it if it is affected.

What it is: CVE-2026-104976 is a high-severity server-side request forgery vulnerability in makeplane plane, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-104976 in the wild and no public exploit code.

Affected product: makeplane plane. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-104976/ (Markdown: https://insights.sbomify.com/CVE-2026-104976/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104976
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104976
- OSV: https://osv.dev/vulnerability/CVE-2026-104976

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104976/
Summaries are generated and may contain mistakes; the official description above is the record.