What is CVE-2026-25776?

CVE-2026-25776 is a critical-severity vulnerability in Six Apart Ltd. Movable Type, classified under Code Injection. CVSS score: 9.8/10. Published 2026-04-08.

How severe is CVE-2026-25776?

Critical severity. CVSS v3 base score is 9.8 out of 10.

RCE in Six Apart Ltd. Movable Type

CVE-2026-25776

Movable Type provided by Six Apart Ltd. contains a code injection vulnerability which may allow an attacker to execute arbitrary Perl script.

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.001 (20.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Six Apart Ltd. Movable Type — versions 9.1.0 and earlier, 9.0.6 and earlier, 8.8.2 and earlier
Six Apart Ltd. Movable Type Advanced — versions 9.1.0 and earlier, 9.0.6 and earlier, 8.8.2 and earlier
Six Apart Ltd. Movable Type Premium — versions 9.1.0 and earlier, 9.0.6 and earlier, 2.14 and earlier
Six Apart Ltd. Movable Type Premium Advanced Edition — versions 9.1.0 and earlier, 9.0.6 and earlier, 2.14 and earlier
Six Apart Ltd. Movable Type Premium (Mt8-based) — versions 2.14 and earlier

Weakness classification (CWE)

CWE-94 — Code Injection

References

Frequently asked questions

What is CVE-2026-25776?: CVE-2026-25776 is a critical-severity vulnerability in Six Apart Ltd. Movable Type, classified under Code Injection. CVSS score: 9.8/10. Published 2026-04-08.
How severe is CVE-2026-25776?: Critical severity. CVSS v3 base score is 9.8 out of 10.