CVE-2026-89087

Incorrect buffer results via subview offset mishandling

Published Sep 10, 2026 · Updated Sep 10, 2026

Index-handling errors in OCaml Cstruct before 6.3.0 allow attackers to obtain incorrect buffer results via unspecified vectors. The filter_map, reverse tail and cuts, and find and find_sub helpers mishandle indexes or fail to preserve a subview's offset when operating on its underlying Bigarray. Reachability depends on a consuming application invoking these helpers on a view, and the public record does not document a security boundary crossed.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Index-handling errors in OCaml Cstruct before 6.3.0 allow attackers to obtain incorrect buffer results via unspecified vectors. The filter_map, reverse tail and cuts, and find and find_sub helpers mishandle indexes or fail to preserve a subview's offset when operating on its underlying Bigarray. Reachability depends on a consuming application invoking these helpers on a view, and the public record does not document a security boundary crossed.

The record

CVE
CVE-2026-89087
Published
Sep 10, 2026
Updated
Sep 10, 2026
Vendor
OCaml
Product
Cstruct
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0 <6.3.0

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

OCaml · Cstructversion=0 <6.3.0

Published CVSS scores

No CVSS assessment is available in this record.

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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Technologies

Your stack

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Your stack

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