CVE-2026-104458: YesWiki before 4.6.7 SSRF Guard Bypass via IPv6 Transition Addresses

Severity: medium (CVSS 6.5 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 in validateKeyIdUrl() that allows unauthenticated attackers to bypass the SSRF guard using 6to4, NAT64, or IPv4-compatible IPv6 addresses. Attackers can send a crafted Signature keyId to the public actor inbox route to reach cloud metadata, loopback services, or internal hosts.

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-85f2-5r47-2pwm
https://www.vulncheck.com/advisories/yeswiki-before-4.6.7-ssrf-guard-bypass-via-ipv6-transition-addresses
https://github.com/YesWiki/yeswiki/security/advisories/GHSA-85f2-5r47-2pwm

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