Quick answers
- Is CVE-2026-121752 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-121752 being exploited in the wild.
- How severe is CVE-2026-121752?
- High severity, with a CVSS score of 7.8, published 12 November 2026.
- Which products and versions are affected?
- Ashlar-Vellum Cobalt.
- Is there a fix for CVE-2026-121752?
- No fixed version is recorded yet. Restrict user interaction with untrusted LI files and avoid opening files from untrusted sources until a patch is available. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-121752 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-121752?
- Check whether you run Ashlar-Vellum Cobalt. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
Restrict user interaction with untrusted LI files and avoid opening files from untrusted sources until a patch is available.
Technical details
The vulnerability exists in the LI file parsing routine of Ashlar-Vellum Cobalt, where insufficient validation of user-supplied data length prior to copying to a heap-based buffer enables a heap-based buffer overflow. The flaw can be triggered remotely through a specially crafted LI file, allowing an attacker to execute arbitrary code in the process context. User interaction (opening a malicious file or visiting a malicious page) is required for exploitation.
Affected products
- Ashlar-Vellum Cobalt
Timeline
- 2025-12-04: disclosed
- 2026-11-04: advisory
- 2026-11-12: other: Published to NVD