Pixelfed SearchController validateUrl remote-search server-side request forgery

Summaryinfo

A vulnerability has been found in Pixelfed and classified as critical. This affects the function validateUrl of the component SearchController. This manipulation of the argument remote-search causes server-side request forgery. The identification of this vulnerability is CVE-2026-71246. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Pixelfed (the affected version unknown). It has been declared as critical. Affected by this vulnerability is the function validateUrl of the component SearchController. The manipulation of the argument remote-search with an unknown input leads to a server-side request forgery vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Pixelfed's SearchController (behind the auth middleware) accepts a URL via its remote-search parameters and fetches it server-side through ActivityPubFetchService, whose validateUrl() only blocks the literal hosts 127.0.0.1, localhost, and ::1 and requires https, without checking the resolved IP against private, internal, or link-local ranges (e.g. 169.254.169.254). Optional DNS validation is disabled by default and, when enabled, only confirms a DNS record exists without filtering by IP range. The fetch response body is returned to the requester only when the Content-Type matches an ActivityPub content type, making this a semi-blind but authenticated SSRF primitive reachable by any logged-in user.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-71246 since 08/05/2026. The exploitation appears to be easy. The attack can be launched 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 08/05/2026).

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

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• Pixelfed

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CPE 2.2info

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