Quick answers
- Is CVE-2026-116203 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-116203 being exploited in the wild.
- How severe is CVE-2026-116203?
- Medium severity, with a CVSS score of 6.1, published 25 October 2026.
- Which products and versions are affected?
- YesWiki before 4.7.0.
- Is there a fix for CVE-2026-116203?
- Yes: fixed in 4.7.0. Until then: Restrict write access to trusted users only by setting write=* to a specific user group or authentication requirement in the page ACL configuration, reducing the number of unauthenticated attackers who can inject malicious content. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-116203 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-116203?
- Check whether you run YesWiki 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: 4.7.0
Restrict write access to trusted users only by setting write=* to a specific user group or authentication requirement in the page ACL configuration, reducing the number of unauthenticated attackers who can inject malicious content.
Technical details
The filtertags action in YesWiki echoes attacker-controlled tag names and parameter values without proper HTML encoding in tools/tags/actions/filtertags.php. The vulnerability exists because the action-parameter syntax is processed before the allow_raw_html security gate, allowing unauthenticated attackers to inject arbitrary markup via attributes like filter1="<img src=x onerror=...>" that bypasses content filtering restrictions. An attacker can store JavaScript that executes for every subsequent viewer of the compromised page.
Affected products
- YesWiki YesWiki before 4.7.0
Timeline
- 2026-10-09: disclosed
- 2026-10-25: advisory