CVE-2026-120263
Gitea OAuth2 account auto-linking takeover through the sign-up form
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.
INFO
Published Date :
Nov. 1, 2026, 10:18 a.m.
Last Modified :
Nov. 1, 2026, 10:18 a.m.
Remotely Exploit :
No
Source :
88ee5874-cf24-4952-aea0-31affedb7ff2
Affected Products
The following products are affected by CVE-2026-120263
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Ensure ACCOUNT_LINKING is not set to auto.
- Verify existing account matches provider's email.
- Require account password if match fails.
- Review OAuth2 provider settings.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-120263.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes 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.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-120263 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-120263 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 88ee5874-cf24-4952-aea0-31affedb7ff2
Nov. 01, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-287 Added CWE CWE-639 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/120xxx/CVE-2026-120263.json">CVE-2026-120263</a> Added Reference https://blog.gitea.com/release-of-28.3.0/ Added Reference https://github.com/go-gitea/gitea/pull/40121 Added Reference https://github.com/go-gitea/gitea/pull/40137 Added Reference https://github.com/go-gitea/gitea/releases/tag/v28.3.0 Added Reference https://github.com/go-gitea/gitea/security/advisories/GHSA-8p3x-w464-4g6v