CVE-2026-52762
Fix: YesWiki/yeswiki@89462f1CVE-2026-52762 is a CWE-1336 vulnerability in yeswiki/yeswiki. O3 Security confirms whether CVE-2026-52762 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
YesWiki: Authenticated (Admin) Server-Side Template Injection to Remote Code Execution via Bazar Semantic Templates
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-52762.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
yeswiki/yeswikiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
YesWiki is a wiki system written in PHP. Prior to version 4.6.6, YesWiki Bazar contains a stored Server-Side Template Injection (SSTI) vulnerability in the semantic template feature that can be escalated to confirmed Remote Code Execution (RCE). An authenticated administrator can place arbitrary Twig expressions into the Semantic template (Twig) field (bn_sem_template), and that content is later executed server-side when public semantic endpoints are requested. This issue has been patched in version 4.6.6.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | yeswiki/yeswiki | all versions | 4.6.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yeswiki/yeswiki. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update yeswiki/yeswiki to 4.6.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52762 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-52762 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-52762. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-52762 in your dependencies?
O3 detects CVE-2026-52762 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.