Deserialization in Miniorange Headless Single Sign On

CVE-2026-28149

Unauthenticated PHP Object Injection in Headless Single Sign On <= 1.6 versions.

Vulnerability class: Insecure Deserialization

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (44.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.6% 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-2026-28149: held from 0.004 to 0.006.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-28149?
CVE-2026-28149 is a critical-severity vulnerability in Miniorange Headless Single Sign On, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-08-13.
How severe is CVE-2026-28149?
Critical severity. CVSS v3 base score is 9.8 out of 10.