Description
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. Prior to versions 1.12.4 and 1.18.0, ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses. ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after. This issue may lead to remote Denial of Service (DoS). Versions 1.12.4 and 1.18.0 fix 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 | < 1.12.4 | 1.12.4 | GHSA-92rq-c8cf-prrq |
| RubyGems | ruby-saml | >= 1.13.0, < 1.18.0 | 1.18.0 | GHSA-92rq-c8cf-prrq |
Advisories 3
- 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-2025-0561 Ruby SAML: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 6, 2025
References
- https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-92rq-c8cf-prrq
- https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv
- https://github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a
- https://github.com/SAML-Toolkits/ruby-saml/commit/e2da4c6dae7dc01a4d9cd221395140a67e2b3eb1
- 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://securitylab.github.com/advisories/GHSL-2024-355_ruby-saml