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Vulnerability details: VCID-rxn8-pfdu-uqd3
Vulnerability ID VCID-rxn8-pfdu-uqd3
Aliases CVE-2025-66567
GHSA-9v8j-x534-2fx3
Summary The ruby-saml library is for implementing the client side of a SAML authorization. ruby-saml versions up to and including 1.12.4 contain an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, generating entirely different document structures from the same input. This allows an attacker to execute a Signature Wrapping attack. This issue is fixed in version 1.18.0.
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-347 Improper Verification of Cryptographic Signature
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2025-66567
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2025-66567
cvssv4 9.3 https://github.com/advisories/GHSA-754f-8gm6-c4r2
generic_textual CRITICAL https://github.com/advisories/GHSA-754f-8gm6-c4r2
ssvc Track https://github.com/advisories/GHSA-754f-8gm6-c4r2
cvssv3.1_qr CRITICAL https://github.com/advisories/GHSA-9v8j-x534-2fx3
cvssv4 9.3 https://github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.yml
generic_textual CRITICAL https://github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.yml
cvssv4 9.3 https://github.com/SAML-Toolkits/ruby-saml
generic_textual CRITICAL https://github.com/SAML-Toolkits/ruby-saml
cvssv4 9.3 https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
generic_textual CRITICAL https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
ssvc Track https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
cvssv3 9.1 https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
cvssv3.1_qr CRITICAL https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
cvssv4 9.3 https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
generic_textual CRITICAL https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
ssvc Track https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
cvssv4 9.3 https://nvd.nist.gov/vuln/detail/CVE-2025-66567
generic_textual CRITICAL https://nvd.nist.gov/vuln/detail/CVE-2025-66567
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2025-66567
https://github.com/SAML-Toolkits/ruby-saml
CVE-2025-66567 https://nvd.nist.gov/vuln/detail/CVE-2025-66567
CVE-2025-66567.YML https://github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.yml
e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97 https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
GHSA-754f-8gm6-c4r2 https://github.com/advisories/GHSA-754f-8gm6-c4r2
GHSA-9v8j-x534-2fx3 https://github.com/advisories/GHSA-9v8j-x534-2fx3
GHSA-9v8j-x534-2fx3 https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
No exploits are available.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Found at https://github.com/advisories/GHSA-754f-8gm6-c4r2
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

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passive

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Vector: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-12-09T14:16:33Z/ Found at https://github.com/advisories/GHSA-754f-8gm6-c4r2
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Found at https://github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.yml
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

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present

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passive

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Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Found at https://github.com/SAML-Toolkits/ruby-saml
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

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Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Found at https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

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passive

active

high

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none

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Vector: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-12-09T14:16:33Z/ Found at https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Found at https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

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passive

active

high

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none

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Vector: SSVCv2/E:N/A:Y/T:T/P:M/B:A/M:M/D:T/2025-12-09T14:16:33Z/ Found at https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Found at https://nvd.nist.gov/vuln/detail/CVE-2025-66567
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

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Exploit Prediction Scoring System (EPSS)
Percentile 0.16104
EPSS Score 0.0005
Published At June 11, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-11T16:59:48.674036+00:00 Vulnrichment Import https://github.com/cisagov/vulnrichment/blob/develop/2025/66xxx/CVE-2025-66567.json 38.6.0