CVE-2026-15013
CRITICALCVSS v3
9.8
CRITICAL
EPSS Score
—
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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 sec
Technical Details
- CVSS v3 Vector
- 3.1
- Published
- 7/16/2026
- Last Modified
- 7/16/2026
Frequently Asked Questions
What is CVE-2026-15013?
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 sec
Is CVE-2026-15013 actively exploited?
Active exploitation of CVE-2026-15013 has not been confirmed. The EPSS score is N/A%, indicating the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2026-15013?
CVE-2026-15013 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string 3.1.
Is CVE-2026-15013 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.