CVE-2025-25293 | ruby-saml vulnerable to Remote Denial of Service (DoS) with compressed SAML responses

Exp

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.

Published: 2025-03-12 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-25293 is rated High Exploit Risk (64.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.36%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2025-25293

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2025-25293

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 6.22% 1.36% -4.87%
2 2026-05-07 5.26% 6.22% +0.97%
3 2026-04-21 — 5.26% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-25293

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.7 4.0 HIGH
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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:P)
Proof-of-concept: public PoC exists; no reported exploitation and no known simplification tools.
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-25293

GitHub Security Advisory for CVE-2025-25293

GHSA-92rq-c8cf-prrq · Severity: high · Ecosystem: rubygems — Ruby SAML allows remote Denial of Service (DoS) with compressed SAML responses

OS Trackers for CVE-2025-25293

vendor priority summary link
debian end-of-life CVE-2025-25293 end-of-life priority: Debian including 1 source packages (ruby-saml), 2 status rows across 2 suites (bookworm, bullseye): open 1, resolved 1. https://security-tracker.debian.org/tracker/CVE-2025-25293
ubuntu medium CVE-2025-25293 medium priority: Ubuntu including 1 source packages (ruby-saml), 9 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream, xenial): released 7, DNE 1, ignored 1. https://ubuntu.com/security/CVE-2025-25293

Affected software / configurations for CVE-2025-25293

Vendor Product Version Raw CPE
omniauth omniauth_saml < 1.10.6 cpe:2.3:a:omniauth:omniauth_saml:*:*:*:*:*:ruby:*:*
omniauth omniauth_saml >= 2.0.0, < 2.1.3 cpe:2.3:a:omniauth:omniauth_saml:*:*:*:*:*:ruby:*:*
omniauth omniauth_saml >= 2.2.0, < 2.2.3 cpe:2.3:a:omniauth:omniauth_saml:*:*:*:*:*:ruby:*:*
onelogin ruby-saml < 1.12.4 cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:*
onelogin ruby-saml >= 1.13.0, < 1.18.0 cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:*

References for CVE-2025-25293

URL Tags
https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released Patch
https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials Exploit Third Party Advisory
https://github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a Patch
https://github.com/SAML-Toolkits/ruby-saml/commit/e2da4c6dae7dc01a4d9cd221395140a67e2b3eb1 Patch
https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4 Release Notes
https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0 Release Notes
https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-92rq-c8cf-prrq Vendor Advisory
https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv Vendor Advisory
https://securitylab.github.com/advisories/GHSL-2024-355_ruby-saml Exploit Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/04/msg00011.html
https://security.netapp.com/advisory/ntap-20250314-0008/ Third Party Advisory
cvelogic Threat Intelligence