CVE-2026-19781

Received Received - Intake

Heap-based Buffer Overflow in Ashlar-Vellum Cobalt

Publication date: 2026-09-15

Last updated on: 2026-09-15

Assigner: Zero Day Initiative

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-15

Last Modified

2026-09-15

Generated

2026-10-06

AI Q&A

2026-09-16

EPSS Evaluated

2026-10-04

NVD

CVE-2026-19781

EUVD

EUVD-2026-79134

Affected Vendors & Products

Vendor	Product	Version / Range
ashlar-vellum	cobalt	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This is a heap-based buffer overflow vulnerability in Ashlar-Vellum Cobalt that allows remote attackers to execute arbitrary code. The issue occurs when parsing VS files due to insufficient validation of user-supplied data length before copying it to a heap-based buffer. Exploitation requires user interaction, such as visiting a malicious page or opening a malicious file.

Detection Guidance

Detection primarily involves monitoring for suspicious activity during VS file parsing. Check for crashes or unusual memory usage in Ashlar-Vellum Cobalt processes when opening VS files. Enable application logging and inspect logs for errors related to heap-based buffer overflows or memory corruption.

Impact Analysis

An attacker could exploit this vulnerability to run malicious code on your system, potentially leading to data theft, system compromise, or further network infiltration. Since user interaction is required, you would need to open a malicious file or visit a compromised webpage for the attack to succeed.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR and HIPAA requirements for data protection and confidentiality. Organizations affected by this flaw may face compliance violations, legal penalties, and reputational damage if exploited.

Mitigation Strategies

Update Ashlar-Vellum Cobalt to version 12.6.1204.210 or later, which includes the fix. Avoid opening VS files from untrusted sources. Implement network monitoring to block malicious file downloads. Restrict user permissions to minimize potential impact if exploitation occurs.

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