CVE-2026-41083VulnerabilityPublished 18 Jun 2026Updated 10 Sep 2026

CVE-2026-41083: Ocaml · Windows command execution via filename quotes

Affects ocamlSource GCVE Database

Not known to be exploited · CVSS 6.1 Medium · fixed in d5c65dc0034fbd75f10c6b54028e8b2740a7b189 : update ocaml when convenient.

Data as of 10 Sep 2026, 13:26 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in d5c65dc0034fbd75f10c6b54028e8b2740a7b189, ce6d0f7b67145debec57e296dcc49d8619259198, 39d3f110eab62ab9f3013bb5f084af2dc3e3bb08 +2

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Jun 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 wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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

Upgrade to a fixed release listed under Affected software.

Patches and advisories

github.com/ocaml/ocaml/pull/14853 (opens in a new tab)

Affected software

Product	Affected	Fixed in
opamocaml`pkg:opam/ocaml`Other threats	Affected <4.14.4 >=5 <5.5.0 <ce6d0f7b67145debec57e296dcc49d8619259198 <39d3f110eab62ab9f3013bb5f084af2dc3e3bb08 <d5c65dc0034fbd75f10c6b54028e8b2740a7b189 =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 =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	Fixed in 4.14.4 5.5.0 ce6d0f7b67145debec57e296dcc49d8619259198 39d3f110eab62ab9f3013bb5f084af2dc3e3bb08 d5c65dc0034fbd75f10c6b54028e8b2740a7b189

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AI-suggested

A patch is available and has been released in OCaml version 4.14.4. Users should upgrade to version 4.14.4 or later to remediate this vulnerability. The fix is documented in the official OCaml pull request https://github.com/ocaml/ocaml/pull/14853. No additional mitigations are indicated by the vendor advisory.

Description

A vulnerability in OCaml on Windows allows command injection via improper quoting of stdin/stdout/stderr filenames. The function Filename.quote_command does not sufficiently escape the '&' character, enabling an attacker to inject shell commands if they can control these file descriptors. This issue affects multiple OCaml versions prior to 4.14.4 and certain 5.x versions. A fix has been released in OCaml 4.14.4.

Impact

An attacker able to control the stdin, stdout, or stderr parameters of a program executed via Filename.quote_command on Windows can execute arbitrary shell commands. This can lead to unauthorized command execution with the privileges of the OCaml process. The CVSS score is 6.1 (medium severity), reflecting local attack vector with low complexity and no user interaction required, impacting confidentiality and integrity.

Summary

The vulnerability (CVE-2026-41083) arises because the quoting mechanism used by OCaml's Filename.quote_command on Windows does not properly escape the '&' character. This allows an attacker who can specify the stdin, stdout, or stderr of a program to inject additional shell commands. The advisory includes an example where an attacker uses the '&' character in a filename to execute the 'tasklist' command. The issue was reported in April 2026 and fixed in OCaml 4.14.4, with the fix merged in June 2026.

References

github.com/ocaml/ocaml/pull/14853 (opens in a new tab)

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