CVE-2026-25776Network attack vector

Unauthenticated Perl code execution via filter processing

Published Apr 8, 2026 · Updated Apr 8, 2026

Code injection in Six Apart Ltd. Movable Type 9.1.0 and earlier allows remote attackers to execute arbitrary Perl code through filter processing. Six Apart has not published the exact filter parameter or unsafe evaluation operation that converts untrusted filter input into executable Perl. The flaw is reachable without authentication when the Listing Framework is enabled in the administrative console or the Data API is available, giving code execution in the server process context.

CVSS severity9.3
Critical
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Six Apart Ltd. Movable Type 9.1.0 and earlier allows remote attackers to execute arbitrary Perl code through filter processing. Six Apart has not published the exact filter parameter or unsafe evaluation operation that converts untrusted filter input into executable Perl. The flaw is reachable without authentication when the Listing Framework is enabled in the administrative console or the Data API is available, giving code execution in the server process context.

The record

CVE
CVE-2026-25776
Published
Apr 8, 2026
Updated
Apr 8, 2026
Vendor
Six Apart Ltd.
Product
Movable Type Advanced
Classifications
CWE-94, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.0.9 and earlier
  2. Affected versionversion=8.8.2 and earlier
  3. Affected versionversion=9.0.6 and earlier
  4. Affected versionversion=9.1.0 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Six Apart Ltd. · Movable Type Advancedversion=8.0.9 and earlier; version=8.8.2 and earlier; version=9.0.6 and earlier; version=9.1.0 and earlier
Six Apart Ltd. · Movable Type Premiumversion=2.14 and earlier; version=9.0.6 and earlier; version=9.1.0 and earlier
Six Apart Ltd. · Movable Type Premium (Advanced Edition)version=2.14 and earlier; version=9.0.6 and earlier; version=9.1.0 and earlier
Six Apart Ltd. · Movable Typeversion=1.0 to 1.68; version=5.1 to 5.18; version=5.2; version=5.2.1 to 5.2.13; version=6.0; version=6.0.1 to 6.8.8; version=7 r.4207 to r.5510; version=8.0.9 and earlier; version=8.4.0 to 8.4.4; version=8.8.2 and earlier; version=9.0.6 and earlier; version=9.1.0 and earlier

Published CVSS scores

9.3JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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