CVE-2026-120263

CRITICAL
INFO Priority: 0.02 BB Relevance: 80/100
Published: 2026-11-01 Modified: 2026-11-06 First seen: 2026-11-01 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: High
I: High
A: High

Description

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.

Affected Software (2)

VendorProductVersion
Gitea Gitea 0 < 28.3.0
Gitea Gitea 0 < 28.3.0

Bug Bounty Relevance

80 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

9.8 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.16%
Raw Score 0.001620
Percentile 5.5%
Date 2026-11-06

EPSS Trend

2026-11-06
0.00162
2026-11-05
0.00162
2026-11-04
0.00162
2026-11-03
0.00162
2026-11-02
0.00162
2026-11-01
0.00198

Intelligence Sources

mitre ref →
nvd ref →