CVE-2025-59055 InstantCMS vulnerable to Server-Side Request Forgery via package installer

Medium 4.7 Published 11 Sep 2025 Updated 11 Sep 2025

Authenticated attackers can exploit SSRF in InstantCMS to scan networks, access local services, or cause denial of service.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-59055?

CVE-2025-59055 is a medium-severity server-side request forgery vulnerability in instantsoft icms2, published on 11 Sep 2025. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

InstantCMS is a free and open source content management system. A blind Server-Side Request Forgery (SSRF) vulnerability in InstantCMS up to and including 2.17.3 allows authenticated remote attackers to make nay HTTP/HTTPS request via the package parameter. It is possible to make any HTTP/HTTPS request to any website in installer functionality. Due to such vulnerability it is possible to for example scan local network, call local services and its functions, conduct a DoS attack, and/or disclose a server's real IP if it's behind a reverse proxy. It is also possible to exhaust server resources by sending plethora of such requests. As of time of publication, no patched releases are available.

Weakness: CWE-918

Which versions are affected by CVE-2025-59055?

It affects 1 product.

Products include Instantcms Instantcms.

How do I fix CVE-2025-59055?

No fix has been published for CVE-2025-59055 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-2025-59055 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59055 exists.

Sources

Also known as GHSA-79hh-mhvg-whrw.