High severity · published Feb 27, 2026
CVE-2026-28364
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
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OC
OCaml · OCaml
before 4.14.3; 5.0.0 before 5.4.1 · source: vendor, NVD
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28364
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-28364
Vendor Advisory
https://github.com/ocaml/security-advisories/blob/generated-osv/2026/OSEC-2026-01.json
Third Party Advisory
https://osv.dev/vulnerability/OSEC-2026-01
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-28364
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2443348
security.access.redhat.com
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28364.json
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