CVE-2026-28364VulnerabilityPublished 03/17/2026Updated 09/16/2026

SUSE · Security update for ocaml

Affects SUSE Product Security Team SUSESource GCVE Database

Not known to be exploited · fixed in 5.5.1 : patch SUSE Product Security Team SUSE soon.

Data as of 10/25/2026, 16:36:14 UTC

Severity

High

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.5.1, 928e7c8a950db8730e8e84105d3be347cae38f5c, 304654884d0c90b2e4ab673ff88caef38b05c714 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wild: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Patches and advisories

Affected software

Product	Affected	Fixed in
opamocaml`pkg:opam/ocaml`Other threats	Affected <5.5.1 <928e7c8a950db8730e8e84105d3be347cae38f5c <304654884d0c90b2e4ab673ff88caef38b05c714 <428288660cc1f655605347e09e2fbc0b0a404660 =3.07 =3.07+1 =3.07+2 =3.08.0 =3.08.1 =3.08.2 =3.08.3 =3.08.4 =3.09.0 =3.09.1 =3.09.2 =3.09.3 =3.10.0 =3.10.1 =3.10.2 =3.11.0 =3.11.1 =3.11.2 =3.12.0 =3.12.1 =4.00.0 =4.00.1 =4.01.0 =4.02.0 =4.02.1 =4.02.2 =4.02.3 =4.02.4 =4.03.0 =4.03.1 =4.04.0 =4.04.1 =4.04.2 =4.04.3 =4.05.0 =4.05.1 =4.06.0 =4.06.1 =4.06.2 =4.07.0 =4.07.1 =4.07.2 =4.08.0 =4.08.1 =4.08.2 =4.09.0 =4.09.1 =4.09.2 =4.10.0 =4.10.1 =4.10.2 =4.10.3 =4.11.0 =4.11.1 =4.11.2 =4.11.3 =4.12.0 =4.12.1 =4.12.2 =4.13.0 =4.13.1 =4.13.2 =4.14.0 =4.14.1 =4.14.2 =4.14.3 =4.14.4 =4.14.5 =5.0.0 =5.0.1 =5.1.0 =5.1.1 =5.1.2 =5.2.0 =5.2.1 =5.2.2 =5.3.0 =5.3.1 =5.4.0 =5.4.1 =5.4.2 =5.5.0	Fixed in 5.5.1 928e7c8a950db8730e8e84105d3be347cae38f5c 304654884d0c90b2e4ab673ff88caef38b05c714 428288660cc1f655605347e09e2fbc0b0a404660

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AI-suggested

A patch is available and was released in OCaml version 5.5.1. Users should upgrade to OCaml 5.5.1 or later to remediate this vulnerability. The vendor advisory confirms the fix was merged into the 5.5, 4.14, and trunk branches. No additional mitigations are indicated or required beyond applying the official patch.

Description

This update for ocaml fixes the following issues: - CVE-2026-28364: missing bounds validation in readblock() can lead to arbitrary code execution (bsc#1258992)

Impact

Successful exploitation allows an attacker to cause out-of-bounds heap reads during deserialization, potentially leaking sensitive heap memory contents (information disclosure). It can also cause denial of service through crashes (SIGBUS/SIGSEGV). There is no indication of code execution or privilege escalation. The vulnerability impacts confidentiality and availability but not integrity.

Summary

CVE-2026-28364 is an integer overflow in OCaml's Marshal deserializer's length-validation logic. The vulnerability arises because the sum of offset, header length, and data length is computed using unsigned 64-bit addition that can wrap around, allowing an attacker-controlled data length field to bypass bounds checks. This causes the internal pointer 'intern_src_end' to wrap to a location before the input buffer, invalidating all subsequent read boundary checks. As a result, the deserializer can read heap memory beyond the input buffer, leading to out-of-bounds reads. The vulnerability affects the OCaml functions Marshal.from_bytes, Marshal.from_string, and the C API caml_input_value_from_block. Exploits include heap information disclosure and denial of service via crashes. The issue was reported on 2026-08-15, patched by 2026-09-05 in OCaml 5.5.1, and affects many versions prior to 5.5.1.

References

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