Vulnerability · CVE-2026-121744
ZDI-26-870: (0Day) Ashlar-Vellum Cobalt XE File Parsing Stack-based Buffer Overflow Remote Code Execution Vulnerability
Published Nov 4, 2026 · ZDI-26-870: (0Day) Ashlar-Vellum Cobalt
Last checked Nov 5, 2026. A connected source was read within the last 7 days.
Open the advisory
Exploitation likelihood is not on this record for CVE-2026-121744. A missing EPSS score is not a low risk. Compare ZDI-26-870: (0Day) Ashlar-Vellum Cobalt with the linked advisory before you change production.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (ZDI-26-870: (0Day) Ashlar-Vellum Cobalt).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- High7.8
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Not in the current FIRST EPSS dataset
- Remediation
- Not established
- Affected products
- See sources for product scope
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-2026-121744.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-121744
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for CVE-2026-121744. A missing EPSS score is not a low risk. Compare ZDI-26-870: (0Day) Ashlar-Vellum Cobalt with the linked advisory before you change production.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS is absent from the current FIRST dataset. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Nov 4, 2026 · Zero Day Initiative
Detected
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-2026-121744.
Sources
- CVE.orgVulnerability recordCVE-2026-121744
Official CVE identifier
cve.org - Zero Day InitiativeCoordinated disclosureZDI-26-870
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-2026-121744.
zerodayinitiative.com
Freshness
Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- CVE.orgNov 4, 2026
- Zero Day InitiativeNov 4, 2026