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Fencer Intel
high 7.5

CVE-2025-25293 json

ruby-saml vulnerable to Remote Denial of Service (DoS) with compressed SAML responses

published last yr. modified 2mo ago also BIT-gitlab-2025-25293 , EUVD-2025-6413 , GHSA-92rq-c8cf-prrq

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

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.

Patch / fix

  • rubygems ruby-saml 1.12.4, 1.18.0
  • bitnami gitlab 17.9.2
  • onelogin ruby-saml 1.12.4, 1.18.0
  • omniauth omniauth_saml 1.10.6, 2.1.3, 2.2.3
  • gitlab gitlab 17.7.7, 17.8.5, 17.9.2
  • gitlab gitlab_enterprise 17.7.7, 17.8.5, 17.9.2
  • ruby-saml Ubuntu Pro 16.04 LTS 1.1.2-1ubuntu1+esm2
  • ruby-saml Ubuntu Pro 18.04 LTS 1.7.2-1ubuntu0.1~esm2
  • ruby-saml Ubuntu Pro 20.04 LTS 1.11.0-1ubuntu0.1+esm1
  • ruby-saml Ubuntu Pro 22.04 LTS 1.13.0-1ubuntu0.1+esm1
  • ruby-saml Ubuntu Pro 24.04 LTS 1.15.0-1ubuntu0.24.04.1+esm1

ubuntu advisories UBUNTU-CVE-2025-25293

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2025-25293 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

1.53% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.blog https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials referenced PoC, tagged "exploit" by a source, unverified
  • securitylab.github.com https://securitylab.github.com/advisories/GHSL-2024-355_ruby-saml referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.7 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:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 7.7 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:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
rubygems ruby-saml
<1.12.4
>=1.13.0, <1.18.0
1.12.4
1.18.0
bitnami gitlab
<17.9.2
17.9.2

Affected products

  • SAML-Toolkits ruby-saml

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-770 Allocation of Resources Without Limits or Throttling
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.