---
id: CVE-2026-19781
title: >-
  Ashlar-Vellum Cobalt VS File Parsing Heap-based Buffer Overflow Remote Code
  Execution Vulnerability
summary: >-
  Ashlar-Vellum Cobalt VS 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…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
vendor: Ashlar-Vellum
product: Cobalt
affected:
  - Cobalt 1204.204
published: '2026-09-15'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:11:37.410'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-19781'
references:
  - url: 'https://www.zerodayinitiative.com/advisories/ZDI-26-587/'
    label: zdi-disclosures@trendmicro.com
tags:
  - nvd
  - cve.org
epss: 0.00173
epssPercentile: 0.07006
zeroDay: true
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-15T19:22:40.278547Z'
ingestedAt: '2026-09-15T18:41:59.186Z'
---

## Overview

Ashlar-Vellum Cobalt VS 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 VS 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-28173.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.