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VulnerabilityPublished Updated

CVE-2026-89087: OCaml cstruct · Improper Following of Specification by Caller

Affects OCaml cstructSource CVE Database V5

0

Not known to be exploited · CVSS 7.3 High : upgrade to 6.3.0 soon.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score
7.3High
How severe the flaw is on the 0–10 CVSS scale.
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:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
OCamlcstructAffected
  • <6.3.0
Fixed in
  • 6.3.0

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.

References

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