Description
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. An authentication bypass vulnerability was found in ruby-saml prior to versions 1.12.4 and 1.18.0 due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. This issue may lead to authentication bypass. Versions 1.12.4 and 1.18.0 contain a patch for the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| SAML-Toolkits | ruby-saml | < 1.12.4, >= 1.13.0, < 1.18.0 | — |
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+deb11u2 | DLA-4115-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | ruby-saml | 1.15.0-1ubuntu0.24.04.1+esm1 | USN-7409-1 |
| Ubuntu Pro 22.04 LTS | ruby-saml | 1.13.0-1ubuntu0.1+esm1 | USN-7409-1 |
| Ubuntu Pro 20.04 LTS | ruby-saml | 1.11.0-1ubuntu0.1+esm1 | USN-7409-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | ruby-saml | 1.7.2-1ubuntu0.1~esm2 | USN-7409-1 |
| Ubuntu Pro 16.04 LTS | ruby-saml | 1.1.2-1ubuntu1+esm2 | USN-7409-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| RubyGems | ruby-saml | >= 1.13.0, < 1.18.0 | 1.18.0 | GHSA-754f-8gm6-c4r2 |
| RubyGems | ruby-saml | < 1.12.4 | 1.12.4 | GHSA-754f-8gm6-c4r2 |
Advisories 5
- USN-7409-1 ruby-saml vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- DLA-4115-1 ruby-saml - security update Debian Security (DSA / DLA) · Mar 9, 2026
- WID-SEC-2025-0549 GitLab: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 3, 2025
- WID-SEC-2025-0561 Ruby SAML: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 6, 2025
- NCSC-2025-0087 Kwetsbaarheden verholpen in GitLab NCSC-NL (Netherlands) · Mar 14, 2025
References
- https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-754f-8gm6-c4r2
- https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv
- https://github.com/SAML-Toolkits/ruby-saml/commit/e76c5b36bac40aedbf1ba7ffaaf495be63328cd9
- https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
- https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released
- https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0
- https://portswigger.net/research/saml-roulette-the-hacker-always-wins
- https://securitylab.github.com/advisories/GHSL-2024-329_GHSL-2024-330_ruby-saml