CVE Catalog

CVE-2026-52769

HighCVSS 8.3
Published: Translated: NVD NIST

Summary

YesWiki from version 4.6.2 to before 4.6.6 has a vulnerability in the POST /api/forms/{formId}/actor/inbox route, which is publicly exposed. HttpSignatureService::verifySignature() parses the HTTP Signature header and immediately makes a server-side HTTP GET to that URL, before any cryptographic verification. An unauthenticated attacker can make the server issue requests to internal services, including cloud metadata.

Risk Assessment

An attacker can use the server as a proxy to scan ports, enumerate internal services, and potentially access IAM metadata in cloud environments, leading to severe security compromise.

Recommendation

Upgrade to version 4.6.6 and implement URL validation and signature verification before making requests.

Other vulnerabilities in YesWiki

See all
Original NVD description (English source)

YesWiki is a wiki system written in PHP. From version 4.6.2 to before version 4.6.6, the POST /api/forms/{formId}/actor/inbox route - exposed publicly with acl:"public" - accepts an HTTP Signature header whose keyId parameter is a URL. HttpSignatureService::verifySignature() parses the header and immediately makes a server-side HTTP GET to that URL, before any cryptographic verification or URL validation. An unauthenticated remote attacker can therefore make YesWiki issue arbitrary outbound HTTP requests to any host the server can reach - internal services, cloud-metadata endpoints (169.254.169.254), intranet-only admin panels, etc. - and read enough back via timing and error-message oracles to scan ports, enumerate services, and (on a real cloud instance) reach IAM metadata. The only deployment-side precondition is that ActivityPub be enabled on at least one Bazar form. This issue has been patched in version 4.6.6.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS