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. The vulnerability stems from missing bounds validation in the readblock() function, which performs unbounded memcpy() operations using attacker-controlled lengths from crafted Marshal data.

Published: 2026-02-27 Last update: 2026-03-06 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-28364 is rated Low Risk (37/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-28364

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-06 0.04% 0.05% +0.01%
2 2026-03-07 0.05% 0.04% -0.01%
3 2026-03-05 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-28364

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.9 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 4.7 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2026-28364

OS Trackers for CVE-2026-28364

vendor priority summary link
alpine — CVE-2026-28364: 1 source package rows (ocaml); 3 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 3. https://security.alpinelinux.org/vuln/CVE-2026-28364
debian not yet assigned CVE-2026-28364 not yet assigned priority: Debian including 1 source packages (ocaml), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-28364
redhat high — https://access.redhat.com/security/cve/CVE-2026-28364
suse high CVE-2026-28364 severity important: SUSE including 17 source package names (ocaml-4.05.0-150200.15.3.1, ocaml-4.14.2-150600.3.3.1, …), 72 product×package rows across 14 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (14 product lines)): Fixed 72. https://www.suse.com/security/cve/CVE-2026-28364/
ubuntu medium CVE-2026-28364 medium priority: Ubuntu including 1 source packages (ocaml), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): needs-triage 8. https://ubuntu.com/security/CVE-2026-28364

Affected software / configurations for CVE-2026-28364

Vendor Product Version Raw CPE
ocaml ocaml < 4.14.3 cpe:2.3:a:ocaml:ocaml:*:*:*:*:*:*:*:*
ocaml ocaml >= 5.0.0, < 5.4.1 cpe:2.3:a:ocaml:ocaml:*:*:*:*:*:*:*:*

References for CVE-2026-28364

cvelogic Threat Intelligence