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TI-2026-17293 Aliases CVE-2026-21393GHSA-343f-q34x-rjhr

Cross-site scripting in Six Apart Ltd. Movable Type

Priority LOW 22CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Active
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

Movable Type contains a stored cross-site scripting vulnerability in Edit Comment. If crafted input is stored by an attacker, arbitrary script may be executed on a logged-in user's web browser. Note that Movable Type 7 series and 8.4 series, which are End-of-Life (EOL), are affected by the vulnerability as well.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00237 14th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Six Apart Ltd.Movable Type (Software Edition)9.0.4 to 9.0.5 (9.0 series); 8.8.0 to 8.8.1 (8.8 series); 8.0.2 to 8.0.8 (8.0 series)—No fix listedCNA
Six Apart Ltd.Movable Type Advanced (Software Edition)9.0.4 to 9.0.5 (9.0 series); 8.8.0 to 8.8.1 (8.8 series); 8.0.2 to 8.0.8 (8.0 series)—No fix listedCNA
Six Apart Ltd.Movable Type Premium (Software Edition)9.0.4 (MTP 9.0 series); 2.13 and earlier (MTP 2 series)—No fix listedCNA
Six Apart Ltd.Movable Type Premium (Advanced Edition) (Software Edition)9.0.4 (MTP 9.0 series); 2.13 and earlier (MTP 2 series)—No fix listedCNA
Six Apart Ltd.Movable Type (Cloud Edition)9.0.5 (9 series); 8.8.1 (8 series)—No fix listedCNA
Six Apart Ltd.Movable Type Premium (Cloud Edition)9.0.5 (9 series); 2.12 (MTP 2 series)—No fix listedCNA
  • Movable Type (Software Edition) VendorSix Apart Ltd. Affected 9.0.4 to 9.0.5 (9.0 series); 8.8.0 to 8.8.1 (8.8 series); 8.0.2 to 8.0.8 (8.0 series) Fixed in — No fix listed CNA
  • Movable Type Advanced (Software Edition) VendorSix Apart Ltd. Affected 9.0.4 to 9.0.5 (9.0 series); 8.8.0 to 8.8.1 (8.8 series); 8.0.2 to 8.0.8 (8.0 series) Fixed in — No fix listed CNA
  • Movable Type Premium (Software Edition) VendorSix Apart Ltd. Affected 9.0.4 (MTP 9.0 series); 2.13 and earlier (MTP 2 series) Fixed in — No fix listed CNA
  • Movable Type Premium (Advanced Edition) (Software Edition) VendorSix Apart Ltd. Affected 9.0.4 (MTP 9.0 series); 2.13 and earlier (MTP 2 series) Fixed in — No fix listed CNA
  • Movable Type (Cloud Edition) VendorSix Apart Ltd. Affected 9.0.5 (9 series); 8.8.1 (8 series) Fixed in — No fix listed CNA
  • Movable Type Premium (Cloud Edition) VendorSix Apart Ltd. Affected 9.0.5 (9 series); 2.12 (MTP 2 series) Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-21393
  2. 2026-10-03 Alias added: GHSA-343f-q34x-rjhr

References

Other 3

  • TI-2021-04052 OS command injection in Six Apart Ltd. Movable Type CVSS 3.1CRITICAL 9.8
  • TI-2026-20843 Code injection in Six Apart Ltd. Movable Type CVSS 4.0CRITICAL 9.3
  • TI-2026-69104 Code injection in Movable Type upgrade script CVSS 4.0CRITICAL 9.3
  • TI-2022-17791 Code injection in Six Apart Ltd. Movable Type XMLRPC API CVSS 3.1CRITICAL 9.8
  • TI-2026-69105 SQL injection in Movable Type Site Search function CVSS 4.0HIGH 8.8
  • TI-2020-04547 Unrestricted file upload in Six Apart Ltd. Movable Type CVSS 3.1HIGH 8.8
See all 53 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences