CVE-2026-19912
CVE-2026-19912 is a Improper Input Validation vulnerability. O3 Security confirms whether CVE-2026-19912 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
The Kaltura HTML5 player (mwEmbed / html5lib) contains an unauthenticated remote code execution vulnerability caused by unsafe data deserialization and unsanitized filesystem path construction.…
Description
The Kaltura HTML5 player (mwEmbed / html5lib) contains an unauthenticated remote code execution vulnerability caused by unsafe data deserialization and unsanitized filesystem path construction. mwEmbedLoader.php accepts a user‑controlled ServiceUrl, whose response is passed to unserialize(), and the resulting object’s fields are written to a cache path derived from attacker‑supplied uiconf_id without proper path validation. An attacker can write arbitrary files into web‑accessible locations and achieve code execution as the webserver user. Affected versions include html5lib v2.45, v2.103 and earlier, and other v2.x releases exposing the vulnerable endpoint.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. 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.
Remediation status
No patched version of the affected component has shipped for CVE-2026-19912 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-19912 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-2026-19912. 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-2026-19912 in your dependencies?
O3 detects CVE-2026-19912 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.