Critical· 9.8

CVE-2026-15981

The SAML Single Sign On – SSO Login plugin for WordPress has a critical flaw that lets attackers log in as any user without credentials. The bug is caused by a loose check on OpenSSL signature verification, allowing a crafted SAMLResponse to bypass authentication. This can give attackers full control over the site.

publishedJul 23, 2026

last modifiedJul 24, 2026

sourcesNVD

severity · cvss

9.8

critical · how bad it is

exploitation · epss

<1%

43th percentile · chance of exploitation in 30 days

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →

auto-deletes from the system

counting…on Sep 6, 2026

No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.

Who is affected

WordPress sites using the SAML Single Sign On – SSO Login plugin, versions 5.4.4 and earlier.

Real-world impact

An attacker can create a forged SAMLResponse that tricks WordPress into setting an authentication cookie for any user, including administrators, giving them full access to the site.

Why this severity

The CVSS score of 9.8 reflects that the flaw allows complete compromise of confidentiality, integrity, and availability with no authentication or user interaction required.

What to do about it

no official fix yet

No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.

No fix documented in sources

Timeline

How it’s attacked

Attack vectorNetwork (remote)

Attack complexityLow

Privileges requiredNone

User interactionNone needed

ScopeUnchanged

Confidentiality impactHigh

Integrity impactHigh

Availability impactHigh

References & advisories

NVD advisory ↗Search advisories ↗

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →