CVE-2026-89087: OCaml cstruct · Improper Following of Specification by Caller
Affects OCaml cstructSource CVE Database V5
Not known to be exploited · CVSS 7.3 High : upgrade to 6.3.0 soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.3.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 10 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade OCaml cstruct to 6.3.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| OCamlcstruct | Affected
| Fixed in
|
AI-suggested
Users should upgrade to version 6.3.0 or later once available or follow official vendor instructions. No temporary or official fixes are explicitly documented in the provided data.
Description
CVE-2026-89087 is a high-severity vulnerability in the OCaml cstruct package before version 6.3.0. It involves improper handling of indexes, classified under CWE-573 (Improper Following of Specification by Caller). This flaw can lead to impacts on confidentiality, integrity, and availability. The vulnerability affects all versions prior to 6.3.0.