Auth bypass in Saml Single Sign On

CVE-2026-19842

The SAML Single Sign On WordPress plugin before 5.4.7 does not verify the signature of a SAML response before storing the certificate it carries, and offers an administrator a one-click control that promotes that stored certificate to the site's trusted signing certificate, allowing unauthenticated attackers to have a certificate of their own trusted and then authenticate as any user, including an administrator.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (16.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-19842: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

  • Saml Single Sign On

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-19842?
CVE-2026-19842 is a high-severity vulnerability in Saml Single Sign On, classified under Improper Authentication. CVSS score: 8.8/10. Published 2026-08-19.
How severe is CVE-2026-19842?
High severity. CVSS v3 base score is 8.8 out of 10.