CVE-2025-54572: The Ruby SAML library is for implementing the client side of a SAML authorization. In versions 1.18.0 and below, a denial-of-service vulnerability exi...

Description

The Ruby SAML library is for implementing the client side of a SAML authorization. In versions 1.18.0 and below, a denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion. This is fixed in version 1.18.1.

Metrics

CVSS 4.0

6.9/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.36%

27.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published: Jul 30, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-54572?

The Ruby SAML library is for implementing the client side of a SAML authorization. In versions 1.18.0 and below, a denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion. This is fixed in version 1.18.1.

How severe is CVE-2025-54572?

CVE-2025-54572 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2025-54572?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.