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Fencer Intel
critical 9.8

CVE-2018-9838 json

An integer overflow in the `bigarray` serialization module leads to arbitrary code execution

published 2018-04-06 8 y ago modified 2026-11-06 3 d ago also EUVD-2018-21432 , OSEC-2018-01

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.2%
EPSS 4.2% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

The caml_ba_deserialize function in byterun/bigarray.c in the standard library in OCaml 4.06.0 has an integer overflow which, in situations where marshalled data is accepted from an untrusted source, allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via a crafted object.

Patch / fix

  • opam ocaml 4.07.0
  • ocaml Debian 14, Debian 13, Debian 12 4.05.0-11

debian advisories DEBIAN-CVE-2018-9838

  • ocaml Ubuntu Pro 14.04 LTS 4.01.0-3ubuntu3.1+esm1
  • ocaml Ubuntu Pro 16.04 LTS 4.02.3-5ubuntu2+esm1
  • ocaml Ubuntu Pro 18.04 LTS 4.05.0-10ubuntu1+esm1

ubuntu advisories UBUNTU-CVE-2018-9838

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ocaml SLE Software Development Kit 12 SP3 4.03.0-8.6.8
  • ocaml SLE Software Development Kit 11 SP4 4.02.1-4.6.1
  • ocaml SLE Software Development Kit 11 SP4 4.02.1-4.3.2
  • ocaml SLE Software Development Kit 12 SP3 4.03.0-8.3.1

suse advisories SUSE-SU-2018:1493-1SUSE-SU-2018:1494-1SUSE-SU-2018:1075-1SUSE-SU-2018:0983-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-9838 updated cvss 5.6

ocaml: Integer overflow in byterun/bigarray.c:caml_ba_deserialize() allows remote attackers to cause a denial of service or other unspecified impact

  • Red Hat Enterprise Linux 6 ocaml, ocaml-x11, ocaml-emacs, ocaml-camlp4, ocaml-labltk, ocaml-source, +2 more
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 7 ocaml, ocaml-x11, ocaml-emacs, ocaml-camlp4, ocaml-labltk, ocaml-source, +3 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 8 ocaml, ocaml-camlp4, ocaml-labltk, ocaml-runtime, ocaml-ocamldoc, ocaml-compiler-libs
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.17% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
OSV 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
opam ocaml
<4.07.0
4.07.0

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.