CVE-2025-25293: Ruby SAML allows remote Denial of Service (DoS) with compressed SAML responses
Affects ruby-samlSource GCVE Database
Public exploit available · CVSS 7.7 High : upgrade to 1.12.4 as a priority.
Data as of 29 Oct 2026, 22:52 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 7.7 |
|---|
- Patch
- Available – fixed in 1.12.4, 1.18.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 12 Mar 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade ruby-saml to 1.12.4; ruby-saml to 1.18.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| RubyGemsruby-saml | Affected
| Fixed in
|
| RubyGemsruby-saml | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Summary 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. ### Impact This issue may lead to remote Denial of Service (DoS).
References
- github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-92rq-c8cf-prrq (opens in a new tab)
- github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2025-25293 (opens in a new tab)
- github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a (opens in a new tab)
- github.com/SAML-Toolkits/ruby-saml/commit/e2da4c6dae7dc01a4d9cd221395140a67e2b3eb1 (opens in a new tab)
- about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released (opens in a new tab)
- github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials (opens in a new tab)
- github.com/SAML-Toolkits/ruby-saml (opens in a new tab)
- github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4 (opens in a new tab)
- github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0 (opens in a new tab)
- github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-25293.yml (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/04/msg00011.html (opens in a new tab)
- security.netapp.com/advisory/ntap-20250314-0008 (opens in a new tab)
- securitylab.github.com/advisories/GHSL-2024-355_ruby-saml (opens in a new tab)