CVE-2026-19912

Critical

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.

SeverityCritical
CVSS9.8
Exploit probability—
ProductKaltura HTML5 Video Player, html5 library
PublishedAug 25, 2026
First seenAug 25, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Kaltura Kaltura HTML5 Video Player, html5 libraryv ≤ v2.103, 2.45—

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