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.
https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-rrqh-93c8-j966
https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.1
https://github.com/SAML-Toolkits/ruby-saml/pull/770
https://github.com/SAML-Toolkits/ruby-saml/commit/38ef5dd1ce17514e202431f569c4f5633e6c2709
Published: 2025-07-30
Updated: 2025-07-31
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 6.9
Vector: 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
Severity: Medium
EPSS: 0.00042