CVE-2026-55982 — gitea
CRITICALCVE-2026-55982 is a critical-severity (CVSS 9.1) Information Exposure vulnerability in code.gitea.io/gitea. A fix is available for code.gitea.io/gitea — see the affected versions and patch details below.
OIDC userinfo Endpoint Returns Identity Claims Without Enforcing API Token Scopes
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55982.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-55982 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 380,066 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
code.gitea.io/giteaReal-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
The OIDC userinfo endpoint (GET /login/oauth/userinfo) accepts Gitea API tokens as bearer credentials but does not enforce API token scopes before returning identity claims.
A personal access token scoped only to read:misc can successfully retrieve user information from the OIDC userinfo endpoint, even though the same token is denied access to user-related REST API endpoints that enforce scope checks.
As a result, identity information remains accessible through the OIDC endpoint regardless of the scopes assigned to the API token.
Details
Gitea supports scoped personal access tokens and enforces scope checks on user-related REST API endpoints.
For example, a token scoped only to read:misc is denied access to endpoints such as:
| Endpoint | Required Scope |
|---|---|
GET /api/v1/user | read:user |
GET /api/v1/user/emails | read:user |
GET /api/v1/user/orgs | read:organization |
Requests to these endpoints return:
403 Forbidden
with a scope-related error.
However, the same read:misc token can be supplied as a bearer credential to:
GET /login/oauth/userinfo
Authorization: Bearer <token>
and receives a successful response containing identity claims.
Observed claims include:
emailgroups
The groups claim contains organization and team membership information associated with the authenticated user.
This behavior indicates that the OIDC userinfo endpoint accepts API tokens but does not apply scope restrictions before returning identity claims.
PoC
PoC Details
Proof-of-concept code: https://anonymous.4open.science/r/Gitea_PoC-EC93/3_poc_oidc_userinfo_scope_bypass
Reproduction Steps
- Create a personal access token with only the following scope:
read:misc
- Verify that the token cannot access user-related REST API endpoints:
GET /api/v1/user
GET /api/v1/user/emails
GET /api/v1/user/orgs
Each request returns:
403 Forbidden
- Send the same token to the OIDC userinfo endpoint:
GET /login/oauth/userinfo
Authorization: Bearer <read-misc-token>
- Observe that the request succeeds and returns identity claims, for example:
{
"email": "[email protected]",
"groups": [
...
]
}
Impact
Holders of narrowly scoped API tokens can obtain identity information through the OIDC userinfo endpoint regardless of the scopes assigned to the token.
The issue does not provide access to repositories, issues, pull requests, administrative functionality, or data belonging to other users.
Impact is limited to disclosure of identity information associated with the authenticated user. However, it weakens the authorization boundary established by API token scopes because identity claims remain accessible even when the token lacks user- or organization-related scopes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | code.gitea.io/gitea | all versions | 1.27.0go get code.gitea.io/gitea@v1.27.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code.gitea.io/gitea, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update code.gitea.io/gitea to 1.27.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55982 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2026-55982 in your dependencies?
Find it across Go, including transitive dependencies.