CVE-2026-28149
Unauthenticated PHP Object Injection in Headless Single Sign On <=1.6, enabling RCE
Is CVE-2026-28149 being exploited?
Not confirmed. CVE-2026-28149 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.38% probability of exploitation in the next 30 days.
How severe is CVE-2026-28149?
CVE-2026-28149 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-28149?
Not known from our data. No patch reference has been recorded for CVE-2026-28149, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-28149 affect?
CVE-2026-28149 affects Headless Single Sign On <= 1.6, PHP web servers running Headless SSO, Web apps integrating Headless SSO. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-28149?
Isolate or disable SSO, apply WAF rules, restrict access and monitor; install vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated PHP object injection allowing arbitrary deserialization leading to remote code execution, data disclosure, and full app compromise.
Immediate action required
- affected<= 1.6
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.