VulnerabilityPublished 1 Nov 2026

CVE-2026-120263: Gitea · Improper Authentication

Affects GiteaSource CVE Database V5

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Not known to be exploited : upgrade to 28.3.0 soon.

Data as of 1 Nov 2026, 10:07 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in 28.3.0

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 24 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

cwe-639

What to do

Upgrade Gitea and go-gitea/gitea to 28.3.0.

Affected software

Product	Affected	Fixed in
Giteagitea.dev	Affected <28.3.0	Fixed in 28.3.0
GitHubgo-gitea/gitea`pkg:github/go-gitea/gitea`Other threats	Affected <28.3.0	Fixed in 28.3.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Gitea to version 28.3.0 or later, where this vulnerability is fixed. The fix ensures automatic account linking only occurs when the existing account matches the OAuth2 provider's asserted email or user name; otherwise, the account password is required. No other mitigation is necessary once the upgrade is applied.

Description

CVE-2026-120263 is an improper authentication vulnerability in Gitea versions before 28.3.0. When the OAuth2 client setting ACCOUNT_LINKING is set to auto and registration is enabled, the system incorrectly linked external OAuth2 identities to existing Gitea accounts based on submitted user names or emails rather than the identity asserted by the OAuth2 provider. This flaw allowed an attacker with an account on the OAuth2 provider to link their external identity to another user's Gitea account and sign in as that user without a password, including administrator accounts. The vulnerability was fixed in version 28.3.0 by restricting automatic linking to cases where the existing account matches the provider's email or provider-derived user name, otherwise requiring the account password.

Impact

An attacker with an account on a configured OAuth2 provider could link their external identity to any Gitea account by submitting that user's name or email, thereby bypassing password authentication and gaining unauthorized access. This includes the ability to access administrator accounts, leading to potential full compromise of the Gitea instance. The linked account persists for subsequent sign-ins, allowing ongoing unauthorized access.

CWE-287Improper Authentication (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Fake the Source of Data (opens in a new tab)
Utilizing REST's Trust in the System Resource to Obtain Sensitive Data (opens in a new tab)
Session Hijacking (opens in a new tab)
Token Impersonation (opens in a new tab)
Upload a Web Shell to a Web Server (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Nov 2026, 10:07 UTC

WeaknessesCWE-287

Technical details

References

Community reviews

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