Quick answers
- Is CVE-2026-117533 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-117533 being exploited in the wild.
- How severe is CVE-2026-117533?
- Medium severity, with a CVSS score of 4.4, published 27 October 2026.
- Which products and versions are affected?
- REDAXO 5.18.0 to 5.21.3.
- Is there a fix for CVE-2026-117533?
- Yes: fixed in 5.21.4. Until then: Restrict mediapool upload and edit permissions to trusted users only. Alternatively, block SVG uploads entirely by adding 'svg' to the mediapool's blocked_extensions list. At the web server level (e.g., Apache .htaccess), restrict script execution for SVG files in the /media/ directory using Content-Security-Policy: sandbox and X-Content-Type-Options: nosniff headers. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-117533 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-117533?
- Check whether you run REDAXO at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 5.21.4
Restrict mediapool upload and edit permissions to trusted users only. Alternatively, block SVG uploads entirely by adding 'svg' to the mediapool's blocked_extensions list. At the web server level (e.g., Apache .htaccess), restrict script execution for SVG files in the /media/ directory using Content-Security-Policy: sandbox and X-Content-Type-Options: nosniff headers.
Technical details
The vulnerability is a stored cross-site scripting issue in the mediapool's SVG handling. SVG files are moved into the public /media/ folder via rename() before the sanitizer runs, creating a race condition window where unmodified, script-laden uploads are publicly accessible. An attacker with mediapool upload or edit rights can exploit this by either racing requests against the sanitizer (which takes milliseconds to complete) or exhausting server resources (memory_limit or max_execution_time) to prevent sanitization from finishing, leaving the malicious SVG permanently exposed and executable in victims' browser contexts.
Affected products
- REDAXO REDAXO 5.18.0 to 5.21.3
Timeline
- 2026-08-03: disclosed
- 2026-10-27: advisory
- 2026-10-27: patched