Use-After-Free Remote Code Execution in Ashlar-Vellum Cobalt XE
CVE-2026-121753

7.8HIGH

Key Information:

Vendor

Ashlar-vellum

Status
Cobalt
Vendor
CVE Published:
12 November 2026

What is CVE-2026-121753?

The vulnerability involves the Ashlar-Vellum Cobalt XE software's handling of XE file parsing. Specifically, it stems from a flaw that fails to validate object existence before performing operations, leading to a use-after-free condition. This enables remote attackers to execute arbitrary code within the context of the running process, provided that a user opens a malicious file or visits an affected webpage.

Affected Version(s)

Cobalt 1204.207

References

https://www.zerodayinitiative.com/advisories/ZDI-26-872/
x_research-advisory

CVSS V3.0

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.