SAML Single Sign On <= 5.4.3 - Unauthenticated Authentication Bypass via 'SAMLResponse' Parameter Signature Algorithm Confusion
Summary
| CVE | CVE-2026-15013 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-16 05:16:18 UTC |
| Updated | 2026-07-16 13:38:53 UTC |
| Description | The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bypass via SAML Signature Algorithm Confusion in all versions up to, and including, 5.4.3. The vulnerability exists because `Mo_SAML_Utilities::mo_saml_cast_key()` reads the `SignatureMethod` Algorithm attribute directly from the attacker-controlled `SAMLResponse` parameter rather than enforcing the locally configured algorithm, causing the plugin to recast the IdP's RSA public key as an HMAC-SHA1 shared secret and validate the forged signature against it. This makes it possible for unauthenticated attackers to forge a SAML assertion targeting any WordPress account — including administrators — obtain valid WordPress authentication cookies, and achieve full administrator-level account takeover. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.003040000 probability, percentile 0.224650000 (date 2026-07-20)
Problem Types: CWE-347 | CWE-347 CWE-347 Improper Verification of Cryptographic Signature
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Cyberlord92 | SAML Single Sign On SSO Login | affected 5.4.3 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.wordfence.com/threat-intel/vulnerabilities/id/ee95092d-6351-4612-872d-28416... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/includes... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/miniorange-saml-20-single-sign-on/tags/5.4.3/class-mo... | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: lhking (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-07T22:40:44.000Z | Vendor Notified |
| CNA | 2026-07-15T00:00:00.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.