Cobalt: Out-of-bounds Read
CVE-2025-65087 is a high-severity out-of-bounds read vulnerability in Cobalt from Ashlar-Vellum, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Cobalt versions: 12.6.1204.216 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cobalt you run against the affected versions below, and install the vendor's latest release.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Ashlar-Vellum | Cobalt | 12.6.1204.216 and earlier | Not stated |
| Ashlar-Vellum | Xenon | 12.6.1204.216 and earlier | Not stated |
| Ashlar-Vellum | Argon | 12.6.1204.216 and earlier | Not stated |
| Ashlar-Vellum | Lithium | 12.6.1204.216 and earlier | Not stated |
| Ashlar-Vellum | Cobalt Share | 12.6.1204.216 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.4 | High | CNA (hq.dhs.gov) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
An Out-of-Bounds Read vulnerability is present in Ashlar-Vellum Cobalt, Xenon, Argon, Lithium, and Cobalt Share versions 12.6.1204.216 and prior that could allow an attacker to disclose information or execute arbitrary code when a specially crafted VC6 file is being parsed.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/news-events/ics-advisories/icsa-25-329-01Third Party Advisory, US Government Resource
Other vulnerabilities in Cobalt
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Recent Out-of-bounds Read vulnerabilities
- 7.8 High severity
- 7.1 High severity
- 8.3 High severity
- 8.7 High severity
- 7.7 High severity
- 7.3 High severity
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