SSRF in Instantcms

CVE-2025-59055

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.004 (34.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-59055?
CVE-2025-59055 is a medium-severity vulnerability in Instantcms, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.7/10. Published 2025-09-11.
How severe is CVE-2025-59055?
Medium severity. CVSS v3 base score is 4.7 out of 10.
Is CVE-2025-59055 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.