CVE-2023-39427

Code execution via malformed XE file parsing

Published Oct 26, 2023 · Updated Jan 16, 2025

Out-of-bounds write in Cobalt, Xenon, Argon, Lithium, and Cobalt Share v12 SP0 Build (1204.77) allows attackers to execute code. The XE file parser writes beyond an allocated buffer because it does not properly validate user-supplied file data before the write. A local user must open the crafted file; successful exploitation runs code in the current process context.

CVSS severity7.8
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds write in Cobalt, Xenon, Argon, Lithium, and Cobalt Share v12 SP0 Build (1204.77) allows attackers to execute code. The XE file parser writes beyond an allocated buffer because it does not properly validate user-supplied file data before the write. A local user must open the crafted file; successful exploitation runs code in the current process context.

The record

CVE
CVE-2023-39427
Published
Oct 26, 2023
Updated
Jan 16, 2025
Vendor
Ashlar-Vellum
Product
Cobalt
Classifications
CWE-787, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 26, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=v12 SP0 Build (1204.77)

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Ashlar-Vellum · Cobaltversion=v12 SP0 Build (1204.77)
Ashlar-Vellum · Cobalt Shareversion=v12 SP0 Build (1204.77)
Ashlar-Vellum · Xenonversion=v12 SP0 Build (1204.77)
Ashlar-Vellum · Argonversion=v12 SP0 Build (1204.77)
Ashlar-Vellum · Lithium CADversion=v12 SP0 Build (1204.77)

Published CVSS scores

7.8ICS-CERTCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002User Execution: Malicious File
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo