Vulnerability · Published Aug 25, 2026 · Assigned by certcc
CVE-2026-19912CVE-2026-19912
Critical 9.8
In plain English
A critical-severity improper input validation in Kaltura HTML5 Video Player, html5 library from Kaltura. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 63% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Kaltura | Kaltura HTML5 Video Player, html5 library | 0 – through v2.1032.45 |
Weakness: CWE-20, CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H