go-gitea Gitea up to 1.27.3 URL Validation ALLOWED_DOMAINS/ALLOW_LOCALNETWORKS server-side request forgery

Summaryinfo

A vulnerability marked as critical has been reported in go-gitea Gitea up to 1.27.3. Affected by this vulnerability is an unknown functionality of the component URL Validation. Performing a manipulation of the argument ALLOWED_DOMAINS/ALLOW_LOCALNETWORKS results in server-side request forgery. This vulnerability is cataloged as CVE-2026-96400. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, was found in go-gitea Gitea up to 1.27.3. This affects an unknown code of the component URL Validation. The manipulation of the argument ALLOWED_DOMAINS/ALLOW_LOCALNETWORKS with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

With `[migrations] ALLOWED_DOMAINS` set to a matching entry such as `*` or a hostname wildcard, Gitea's migration URL validation could permit reserved and link-local addresses, such as `169.254.169.254`, even when `ALLOW_LOCALNETWORKS = false`. The local-network block list did not cover these ranges, and a hostname matching the allow list was accepted regardless of its resolved address. A user who can start migrations on such an instance could reach these addresses from the Gitea server; the default empty `ALLOWED_DOMAINS` configuration is not affected.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-96400 since 10/04/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/08/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3792). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Open Source Gitea

Productinfo

Vendor

• go-gitea

Name

• Gitea

Version

• 1.27.0
• 1.27.1
• 1.27.2
• 1.27.3

License

• open-source

Website

• Product: https://github.com/go-gitea/gitea/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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