CVE-2026-104463: YesWiki before 4.6.7 Unauthenticated SSRF via ActivityPub Inbox

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-02 · updated 2026-10-02
Weakness: CWE-918

Description

YesWiki before 4.6.7 contains a server-side request forgery vulnerability that allows unauthenticated attackers to trigger server requests by sending signed Follow activities to the public forms actor inbox route. Attackers sign requests with their own keyId while supplying internal actor URLs in the body, reaching internal hosts or cloud metadata via blind GET and POST requests.

Affected products

yeswiki: before 4.6.7 — fixed in 4.6.7

How to fix

Upgrade to a fixed version: yeswiki 4.6.7. Check the vendor advisory for mitigations.

References

https://github.com/YesWiki/yeswiki/security/advisories/GHSA-x623-wwf6-f6wp
https://www.vulncheck.com/advisories/yeswiki-before-4.6.7-unauthenticated-ssrf-via-activitypub-inbox
https://github.com/YesWiki/yeswiki/security/advisories/GHSA-x623-wwf6-f6wp

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