Cross-site scripting in Six Apart Ltd. Movable Type
Priority LOW 29CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-79.
Summary
Cross-site scripting vulnerability in Website Management screen of Movable Type (Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and earlier (Movable Type Advanced 7 Series), Movable Type Premium 1.44 and earlier, and Movable Type Premium Advanced 1.44 and earlier) allows remote attackers to inject arbitrary script or HTML via unspecified vectors.
Why it matters now
EPSS 0.00904 60th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Six Apart Ltd. | Movable Type | Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and earlier (Movable Type Advanced 7 Series), Movable Type Premium 1.44 and earlier, and Movable Type Premium Advanced 1.44 and earlier | — | No fix listed | CNA |
- Movable Type VendorSix Apart Ltd. Affected Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and earlier (Movable Type Advanced 7 Series), Movable Type Premium 1.44 and earlier, and Movable Type Premium Advanced 1.44 and earlier Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:sixapart:movable_type:*:*:*:*:premium:*:*:* | up to 1.44 | Vulnerable | Sixapart |
| cpe:2.3:a:sixapart:movable_type:*:*:*:*:premium_advanced:*:*:* | up to 1.44 | Vulnerable | Sixapart |
| cpe:2.3:a:sixapart:movable_type:*:*:*:*:-:*:*:* | 6.0 – 6.8.0; 7.0 to before 7.8.0 | Vulnerable | Sixapart |
| cpe:2.3:a:sixapart:movable_type:*:*:*:*:advanced:*:*:* | 7.0 to before 7.8.0 | Vulnerable | Sixapart |
- cpe:2.3:a:sixapart:movable_type:*:*:*:*:premium:*:*:* Versions up to 1.44 Vulnerable ·Sixapart
- cpe:2.3:a:sixapart:movable_type:*:*:*:*:premium_advanced:*:*:* Versions up to 1.44 Vulnerable ·Sixapart
- cpe:2.3:a:sixapart:movable_type:*:*:*:*:-:*:*:* Versions 6.0 – 6.8.0; 7.0 to before 7.8.0 Vulnerable ·Sixapart
- cpe:2.3:a:sixapart:movable_type:*:*:*:*:advanced:*:*:* Versions 7.0 to before 7.8.0 Vulnerable ·Sixapart
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20810
- 2026-10-03 Alias added: GHSA-j9hg-mq8j-8cvg
References
More Six Apart Ltd. vulnerabilities
- 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
Sources
- CVE-2021-20810 · CVE Program
- CVE-2021-20810 · NVD
- FIRST EPSS
- GHSA-j9hg-mq8j-8cvg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences