CVE-2026-28364: High severity ocaml OCaml vulnerability

Published Feb 27, 2026
·
Updated

In OCaml before 4.14.3 and 5.x before 5.4.1, a buffer over-read in Marshal deserialization (runtime/intern.c) enables remote code execution through a multi-phase attack chain. The vulnerability stems from missing bounds validation in the readblock() function, which performs unbounded memcpy() operations using attacker-controlled lengths from crafted Marshal data.

Affected Software

5 affected componentsFixes available
ocaml OCaml<4.14.3, >5.0.0<=5.4.1
ocaml OCaml<4.14.3
ocaml OCaml>=5.0.0<5.4.1
Microsoft cbl2 ocaml 4.13.1-2
Microsoft azl3 ocaml 5.1.1-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade OCaml runtime/intern.c to a version that resolves this vulnerability.

    Fixed in 4.14.3
  2. Upgrade

    Upgrade OCaml runtime/intern.c to a version that resolves this vulnerability.

    Fixed in 5.4.1

Event History

Feb 27, 2026
CVE Published
via MITRE·03:54 AM
Data Sourced
via MITRE·03:54 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:16 AM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·04:01 PM
DescriptionSeverityAffected Software
Feb 28, 2026
Data Sourced
via Microsoft·09:04 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·09:04 AM
Affected Software
Updated
via Microsoft·09:04 AM
DescriptionSeverity
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Frequently Asked Questions

1

What is the severity of CVE-2026-28364?

CVE-2026-28364 is considered a high severity vulnerability due to its potential for remote code execution.

2

How do I fix CVE-2026-28364?

To fix CVE-2026-28364, upgrade to OCaml version 4.14.3 or 5.4.1 or later.

3

What type of vulnerability is CVE-2026-28364?

CVE-2026-28364 is a buffer over-read vulnerability found in the Marshal deserialization process.

4

What software versions are affected by CVE-2026-28364?

CVE-2026-28364 affects OCaml versions prior to 4.14.3 and between 5.0.0 and 5.4.0 inclusive.

5

Can CVE-2026-28364 lead to data breaches?

Yes, CVE-2026-28364 can lead to data breaches through remote code execution if not addressed.

Contact

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