RCE in Sixapart 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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.007 (52.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.003
Affected products
- Sixapart Movable Type — versions 9.0.5, 9.0.6, 9.1.0
- 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)
References
- movabletype.org/news/2026/04/mt-907-released.html (Vendor Advisory)
- www.sixapart.jp/movabletype/news/2026/04/08-1100.html (Vendor Advisory)
- jvn.jp/en/jp/JVN66473735/ (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-25776?
- CVE-2026-25776 is a critical-severity vulnerability in Sixapart 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.