CVE-2025-7985: 
NixOS vulnerability analysis and mitigation

This vulnerability (CVE-2025-7985) affects Ashlar-Vellum Cobalt software and was discovered by Rocco Calvi of TecSecurity. The vulnerability was reported to the vendor on November 21, 2024, and was publicly disclosed on July 22, 2025, as a zero-day vulnerability. It received a CVSS score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) (ZDI Advisory).

The vulnerability exists within the parsing of VC6 files in Ashlar-Vellum Cobalt. The specific flaw results from the lack of proper validation of user-supplied data, which can result in an integer overflow before allocating a buffer. This vulnerability requires user interaction, as the target must visit a malicious page or open a malicious file (ZDI Advisory).

An attacker who successfully exploits this vulnerability can execute arbitrary code in the context of the current process, potentially gaining the same privileges as the logged-in user. The high CVSS score of 7.8 indicates significant potential impact on the confidentiality, integrity, and availability of the affected system (ZDI Advisory).

Given the nature of the vulnerability, the only salient mitigation strategy is to restrict interaction with the product. As of the disclosure date, no official patch was available from the vendor (ZDI Advisory).