CVE-2026-104459 YesWiki before 4.6.7 SSRF via ActivityPub WebFinger actor_handle
Unauthenticated attackers can trigger internal HTTPS requests via crafted WebFinger actor_handle parameters, enabling internal network probing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-104459?
CVE-2026-104459 is a medium-severity server-side request forgery vulnerability in yeswiki, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
YesWiki before 4.6.7 contains a server-side request forgery vulnerability in WebfingerService that allows unauthenticated attackers to trigger HTTPS requests to internal hosts. Attackers can POST a crafted actor_handle with a numeric host and port to the abonnements view to probe internal HTTPS services and ports.
Weakness: CWE-918
Which versions are affected by CVE-2026-104459?
How do I fix CVE-2026-104459?
No fix has been published for CVE-2026-104459 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-104459 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104459 exists.
Sources
Also known as GHSA-pg4j-r96p-6rg4, GHSA-x4mq-qxvc-g82j.