Stored cross-site scripting in phpMyFAQ via SVG DTD entities
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
phpMyFAQ from 4.2.0-alpha before 4.2.0-beta is affected. Its SvgSanitizer fails to neutralize script in uploaded SVG files, allowing stored cross-site scripting (CWE-79) through XML DTD custom entities. A user with FAQ_EDIT permission can upload a crafted SVG, and the script runs when a viewer clicks the link, which can hijack admin sessions.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
phpMyFAQ 4.2.0-alpha before 4.2.0-beta contains a stored cross-site scripting vulnerability in SvgSanitizer that allows users with FAQ_EDIT permission to bypass sanitization using XML DTD custom entities. Attackers can upload an SVG defining an entity that expands to javascript in an anchor href, executing script when viewers click it to hijack admin sessions.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- 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
Remediation
Upgrade phpMyFAQ to 4.2.0-beta, the fixed version.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA phpMyFAQ (thorsten) Fixed in 4.2.0-beta
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
thorsten phpMyFAQ 4.2.0-beta
24 records Highest priority Priority HIGH 10 HIGH, 10 MEDIUM, 4 LOW
Other records, highest priority first
- TI-2026-76108 Unauthenticated denial of service in phpMyFAQ API paginationPriority HIGH 77
- TI-2026-76115 Authorization bypass in phpMyFAQ REST API edits restricted FAQsPriority HIGH 73
- TI-2026-76092 phpMyFAQ e-mail change lacks password check, enabling takeoverPriority HIGH 73
Timeline
- 2026-10-18 Threatist record created from CVE-2026-111903
- 2026-10-18 Alias added: GHSA-4fcw-x9vq-q4pp
- 2026-10-20 CISA SSVC decision points changed
- 2026-10-20 Priority changed: LOW → MEDIUM
References
More thorsten vulnerabilities
- TI-2023-00296 Improper Authentication in thorsten/phpmyfaq CVSS 3.1CRITICAL 9.8
- TI-2026-76118 Authentication bypass in phpMyFAQ via WebAuthn credential injection CVSS 4.0CRITICAL 9.3
- TI-2026-32868 phpMyFAQ - Unauthenticated Two-Factor Authentication Brute-Force via /admin/check Endpoint CVSS 4.0CRITICAL 9.3
- TI-2026-76108 Unauthenticated denial of service in phpMyFAQ API pagination CVSS 4.0HIGH 8.7
- TI-2026-53313 phpMyFAQ 3.1.0 through 4.1.6 Authentication Bypass via LDAP CVSS 4.0HIGH 8.8
- TI-2026-34083 phpMyFAQ - Unauthenticated Information Disclosure via getIdFromSolutionId Permission Bypass CVSS 4.0HIGH 8.7
Sources
- CVE-2026-111903 · CVE Program
- CVE-2026-111903 · NVD
- FIRST EPSS
- GHSA-4fcw-x9vq-q4pp · 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