ZDI-25-956: (0Day) Ashlar-Vellum Cobalt CO File Parsing Use-After-Free Remote Code Execution Vulnerability

Published Oct 16, 2025
·
Updated

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 CO files. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process.

Other sources

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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2025-11465.

ZDI

Affected Software

2 affected components
Ashlar-Vellum Cobalt
Ashlar-Vellum Cobalt

Event History

Oct 16, 2025
Advisory Published
via ZDI·05:00 AM
Data Sourced
via ZDI·05:00 AM
Description
Oct 29, 2025
Advisory Published
via ZDI·07:51 PM
Data Sourced
via ZDI·07:51 PM
SeverityAffected Software

Frequently Asked Questions

1

What is the severity of ZDI-25-956?

The severity of ZDI-25-956 is critical due to the potential for remote code execution by attackers.

2

How do I fix ZDI-25-956?

To fix ZDI-25-956, update your Ashlar-Vellum Cobalt software to the latest version provided by the vendor.

3

Who is affected by ZDI-25-956?

Users of Ashlar-Vellum Cobalt are affected by ZDI-25-956.

4

What type of attack vector is involved in ZDI-25-956?

ZDI-25-956 involves a remote code execution attack that requires user interaction.

5

What can an attacker achieve with ZDI-25-956?

An attacker can execute arbitrary code on affected installations of Ashlar-Vellum Cobalt by exploiting ZDI-25-956.

Contact

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