CVE-2026-52769

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.

CVSS v3 8.3 HIGH

8.3^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope CHANGED

References

Link	Resource
http://github.com/YesWiki/yeswiki/commit/87e627f33e79879827a3669fee2aa1244612c487
https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6
https://github.com/YesWiki/yeswiki/security/advisories/GHSA-vw42-752g-5mrp
https://github.com/YesWiki/yeswiki/security/advisories/GHSA-vw42-752g-5mrp

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-05 00:17

Updated : 2026-09-08 21:05

NVD link : CVE-2026-52769

Mitre link : CVE-2026-52769

CVE.ORG link : CVE-2026-52769

JSON object : View

Products Affected

No product.

CWE

CWE-918

Server-Side Request Forgery (SSRF)

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