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CVE-2026-19912 is an unauthenticated remote code execution vulnerability in Kaltura HTML5 Player mwEmbed/html5lib. A legacy loader accepts an attacker-controlled ServiceUrl, fetches its response, and passes that response to PHP unserialize(). Separately, it appends the attacker-controlled uiconf_id value to a cache-directory path without sufficient validation. An attacker can combine malicious serialized content with directory traversal in uiconf_id to redirect cache writes outside the intended directory, place a PHP payload in a web-accessible location, and execute it. Affected releases include html5lib v2.45, v2.103 and earlier, as well as other exposed v2.x releases.
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1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos.
This four-file repository consists of a README, license, .gitignore, and one Python entry point, kaltura_poc.py. It is a standalone Kaltura mwEmbed/html5lib proof of concept rather than a known exploitation framework module. The Python tool has three CLI modes: fileread, serve, and rce. fileread builds requests to mwEmbedLoader.php with a ServiceUrl file:// value and extracts file bytes reflected after known unserialize-error markers, implementing the claimed unauthenticated arbitrary-file-read issue (CVE-2026-19913). serve launches a threaded Python HTTP server to host selected serialized payloads. rce combines that listener with a target request intended to exploit ServiceUrl plus a uiconf_id traversal/cache/deserialization path (claimed CVE-2026-19912) to place a PHP command web shell. The source itself labels the RCE serialized blobs and object classes as placeholders requiring target-specific inspection and adaptation, so the RCE portion is best assessed as a chain skeleton while the file-read functionality is directly implemented. The README also names CVE-2026-19914, but the supplied code comments and implemented functionality only substantiate CVE-2026-19912 and CVE-2026-19913. No fixed victim host is embedded; target, listener host, ports, versions, requested files, and prospective shell location are operator supplied.
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9 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A critical unauthenticated remote-code-execution vulnerability in Kaltura's mwEmbed/HTML5 player loader. A malicious serialized object supplied through ServiceUrl is deserialized, while path traversal in uiconf_id permits writing executable PHP into a web-accessible directory. The described file-drop path depends on Kaltura's default file-based cache backend.
An unauthenticated remote-code-execution vulnerability in Kaltura HTML5 Player mwEmbed/html5lib. Attacker-controlled ServiceUrl content is deserialized with unserialize(), while an attacker-controlled uiconf_id influences the cache-file path, enabling arbitrary file writes to web-accessible locations and code execution as the webserver user.
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Cross-references every affected SKU, including bundled OEM variants.
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