{"id":"CVE-2026-121743","aliases":["EUVD-2026-124159","GHSA-jqr4-cgc2-3v65"],"status":"published","title":"Ashlar-Vellum Cobalt AR File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability","description":"Ashlar-Vellum Cobalt AR 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.\n\nThe specific flaw exists within the parsing of AR 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-28675.","severity":{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-13","score":0.00212,"percentile":0.11565,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-122"],"published":"2026-11-12T02:51:12Z","modified":"2026-11-12T03:30:34Z","products":[{"vendor":"ashlar-vellum","product":"cobalt"}],"references":[{"url":"https://www.zerodayinitiative.com/advisories/ZDI-26-873/","tags":["x_research-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121743"},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-26-873"},{"url":"https://github.com/advisories/GHSA-jqr4-cgc2-3v65"}],"sources":{"cve":[{"id":"CVE-2026-121743","title":"Ashlar-Vellum Cobalt AR File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability","description":"Ashlar-Vellum Cobalt AR 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.\n\nThe specific flaw exists within the parsing of AR 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-28675.","status":"published","published":"2026-11-12T02:51:12.304Z","modified":"2026-11-12T02:51:12.304Z","cvss":[{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-122"],"updated_at":"2026-11-12T03:36:44.363384Z"}],"euvd":[{"id":"EUVD-2026-124159","description":"Ashlar-Vellum Cobalt AR 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.\n\nThe specific flaw exists within the parsing of AR 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-28675.","status":"published","published":"2026-11-12T02:51:12Z","modified":"2026-11-12T02:51:12Z","cvss":[{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-12T05:31:52.357824Z"}],"ghsa":[{"id":"GHSA-jqr4-cgc2-3v65","title":"Ashlar-Vellum Cobalt AR File Parsing Heap-based Buffer Overflow Remote Code Execution...","description":"Ashlar-Vellum Cobalt AR 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.\n\nThe specific flaw exists within the parsing of AR 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-28675.","status":"published","published":"2026-11-12T03:30:29Z","modified":"2026-11-12T03:30:34Z","cvss":[{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-122"],"updated_at":"2026-11-12T03:37:49.384974Z"}],"nvd":[{"id":"CVE-2026-121743","description":"Ashlar-Vellum Cobalt AR 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.\n\nThe specific flaw exists within the parsing of AR 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-28675.","status":"published","published":"2026-11-12T03:17:10.6Z","modified":"2026-11-12T03:17:10.727Z","cvss":[{"version":"3.0","score":7.8,"vector":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-122"],"updated_at":"2026-11-12T06:28:14.789027Z"}]}}