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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| SAML-Toolkits | ruby-saml | < 1.18.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 12 | ruby-saml | No fix yet | — |
| Debian 11 | ruby-saml | 1.11.0-1+deb11u3 | DLA-4288-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | ruby-saml | No fix yet | — |
| Ubuntu Pro 22.04 LTS | ruby-saml | No fix yet | — |
| Ubuntu Pro 20.04 LTS | ruby-saml | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | ruby-saml | No fix yet | — |
| Ubuntu Pro 16.04 LTS | ruby-saml | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| RubyGems | ruby-saml | < 1.18.1 | 1.18.1 | GHSA-rrqh-93c8-j966 |
Advisories 2
- DLA-4288-1 ruby-saml - security update Debian Security (DSA / DLA) · Mar 9, 2026
- WID-SEC-2025-1686 Ruby SAML: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Aug 31, 2025