Gitea OAuth2 account auto-linking takeover through the sign-up form
CVSS score
—
EPSS probability
%0.2
Risk score
—
Published
5 h ago
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Vulnerability description
DayBreach AI Explanation
Verified against sourcesSources read
2
Source agreement
Tam uyum
Evidence confidence
%63
Short explanation
When OAuth2 account auto-linking is enabled in Gitea, the registration form looks up existing accounts using the submitted username or email instead of the OAuth2 provider's asserted identity. This vulnerability allows attackers to link external identities to another user's account and sign in without a password.
This authentication flaw enables attackers to compromise any user account, including administrator accounts. The persistence of the link affects subsequent sign-ins.
What should be done?
- Follow vendor advisory recommendations
- Review provided patch references
- Upgrade Gitea to unaffected versions
Chain of evidence and sources
Gitea üzerinde [oauth2_client].ACCOUNT_LINKING ayarı auto olduğunda kayıt formu OAuth2 kimliği yerine formda sunulan kullanıcı adını veya e-postayı aratmaktadır.
Saldırgan, yapılandırılmış bir OAuth2 sağlayıcısındaki hesabını kullanarak başka bir kullanıcının adını gönderebilir ve şifresiz olarak yönetici dahil o hesapla oturum açabilir.
Show the technical text from the sources
When `[oauth2_client].ACCOUNT_LINKING` is set to `auto` (not the default) and registration is enabled, the link-account sign-up form looked up the existing account to link by the user name or email submitted in the form instead of the identity asserted by the OAuth2 provider. An attacker with an account on a configured OAuth2 provider could submit another user's name, link their external identity to that Gitea account and be signed in as it without its password, including as an administrator. The link persisted for later sign-ins. Automatic linking now only happens when the existing account matches the provider's email or provider-derived user name; otherwise the account password is required.
CWE: CWE-287, CWE-639
This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-120263 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | gitea | gitea | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| The sources have not yet published a verified CVSS metric. | ||||
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-120263 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-120263 weaknesses.
Official Sources and Advisories
Similar Vulnerabilities
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