Is there a public exploit for CVE-2026-121753?

No public exploit for CVE-2026-121753 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-121753?

CVE-2026-121753 scores CVSS 7.8 (v3.0), rated high.

What does CVE-2026-121753 affect?

CVE-2026-121753 affects Ashlar-Vellum Cobalt.

7.8 High

Ashlar-Vellum Cobalt XE File Parsing Use-After-Free Remote Code Execution Vulnerability.

CVE-2026-121753

Ashlar-Vellum Cobalt XE File Parsing Use-After-Free 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 XE 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. Was ZDI-CAN-28587.

Assessment

CVSS: 7.8 (v3.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 12 November 2026
Last updated: 12 November 2026
Affected: Ashlar-Vellum · Cobalt
Assigner: zdi

CVSS vectorCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

At the source

EUVD (ENISA)

References

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

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