ASHLAR-VELLUM COBALT · CVE-2026-121752 · Other
NO FIX YET · SEE WHAT TO DO
Ashlar-Vellum Cobalt does not check the length of data read from LI files before copying it into a heap buffer. A remote attacker who gets a user to open a malicious file or visit a malicious page can run arbitrary code in the context of the current process.
first public Nov 12, 2026 · 2 sources
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Windows users of Ashlar-Vellum Cobalt who open LI files from untrusted sources. Exploitation needs a user to open a malicious file or visit a malicious page, and code runs as the current process. Teams that never open third-party Cobalt files can deprioritise it.
Not affected if no-untrusted-li-files
Who cares ashlar-vellum, cobalt, desktop, file-parsing, windows
No vendor fix published as of 2026-11-12; ZDI published as a 0-day advisory.
Ashlar-Vellum Cobalt LI File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Ashlar-Vellum Cobalt. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the parsing of LI files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-28447.
This page as .md · .json · CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
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