vulnerability / NVI-00016346 / Revision 2
Gitea: OAuth2 sign-in reactivates an administrator-deactivated account on auth sources without refresh tokens (incomplete fix of #38009)
GitHub lists this reviewed advisory for code.gitea.io/gitea. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
8.1 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.413%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.35701. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
code.gitea.io/gitea
source listed< 1.27.0
## Description Gitea's OAuth2 sign-in callback reactivates a deactivated user account (`IsActive=false`) when the user signs in through an authentication source that does not issue refresh tokens (notably GitHub, and any OIDC/OAuth2 source configured without `offline_access`). PR #38009 added a gate intended to reactivate users only when the OAuth2 auto-sync cron had disabled them, using "the stored refresh token is empty" as the signal. That signal is wrong: for sources that never issue refresh tokens, an empty refresh token is the normal state of every user, so the gate cannot distinguish a cron-disabled account from one an administrator deliberately deactivated. The next time the administrator-deactivated user signs in through the provider, Gitea sets `IsActive=true` and grants a full session, silently undoing the administrator's action. This is the exact behavior #38009 was written to prevent. (`ProhibitLogin`, the hard ban, is enforced separately and is not affected.) No special privileges are required beyond being the deactivated user and being able to sign in through the source. ### Root Cause `routers/web/auth/oauth.go` (the `handleOAuth2SignIn` reactivation gate): ```
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-vrhc-jjfc-m3m3 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-55987 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.