OSEC-2026-24 (CVE-2026-41083)
Vulnerability from osv_ocaml – Published: 2026-10-23 21:30 – Updated: 2026-10-23 21:30 – Source websiteANT-2026-R7FKP7RG Win32 quote_cmd_filename misses pipe/redirect metacharacters
ANT-2026-SRZZ62SD Windows batch-file argument injection via maybe_quote/make_cmdline
ANT-2026-JPEWMPAB Win32 argument quoting leaves embedded CR/LF unescaped
Also includes the fix for OSEC-2026-05
Filename.quote_command returns a quoted command line, suitable for use as an argument to Sys.command, Unix.system, and the Unix.open_process functions.
However on Windows certain characters weren't properly escaped.
Unix.create_process can invoke .bat or .cmd programs on Windows, and certain characters were accepted that cannot be quoted safely.
Fix
Filename.quote_command has been updated to correctly quote arguments.
Unix.create_process* has been updated to reject arguments that cannot be safely quoted by raising Failure:
if the program [prog] is a [.bat] or [.cmd] script and either [prog] or [args] contain characters that cannot be securely passed to a script, such as [" | & , ; < = > ^ % "]. If you really need to pass these characters to a script, consider using {!Unix.system} instead.
Am I affected?
If you use Filename.quote_command on Windows with user supplied arguments.
If you use Unix.create_process* or Unix.open_process* on Windows with .bat or .cmd programs, and user supplied arguments.
Timeline
- 2026-08-24: vulnerability was found
- 2026-08-27: forwarded report to security@ocaml.org
- 2029-09-05: fix merged to trunk
{
"affected": [
{
"ecosystem_specific": {
"affected_bindings": [
"Filename.quote_command",
"Unix.create_process",
"Unix.create_process_env",
"Unix.open_process_args_in",
"Unix.open_process_args_out",
"Unix.open_process_args_full"
],
"opam_constraint": "ocaml {\u003c \"5.5.2\"}"
},
"package": {
"ecosystem": "opam",
"name": "ocaml",
"purl": "pkg:opam/ocaml"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "5.5.2"
}
],
"type": "ECOSYSTEM"
},
{
"events": [
{
"introduced": "0"
},
{
"fixed": "70a3a75c0bfb23d67ad5fe3e9c1ba9800d61feae"
}
],
"repo": "https://github.com/ocaml/ocaml",
"type": "GIT"
},
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0bbf8e5af985feb03a11a5ffe57d068373d09fd0"
}
],
"repo": "https://github.com/ocaml/ocaml",
"type": "GIT"
}
],
"versions": [
"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",
"5.5.1"
]
}
],
"aliases": [
"CVE-2026-41083"
],
"credits": [
{
"name": "Anthropic",
"type": "REPORTER"
},
{
"name": "Hannes Mehnert",
"type": "COORDINATOR"
},
{
"name": "Edwin T\u00f6r\u00f6k",
"type": "COORDINATOR"
},
{
"name": "Nicol\u00e1s Ojeda B\u00e4r",
"type": "REMEDIATION_REVIEWER"
},
{
"name": "Xavier Leroy",
"type": "REMEDIATION_DEVELOPER"
}
],
"database_specific": {
"cwe": [
"CWE-78"
],
"human_link": "https://github.com/ocaml/security-advisories/tree/main/advisories/2026/OSEC-2026-24.md",
"osv": "https://github.com/ocaml/security-advisories/tree/generated-osv/2026/OSEC-2026-24.json"
},
"details": "ANT-2026-R7FKP7RG Win32 quote_cmd_filename misses pipe/redirect metacharacters\n\nANT-2026-SRZZ62SD Windows batch-file argument injection via maybe_quote/make_cmdline\n\nANT-2026-JPEWMPAB Win32 argument quoting leaves embedded CR/LF unescaped\n\nAlso includes the fix for [OSEC-2026-05](https://osv.dev/vulnerability/OSEC-2026-05)\n\n`Filename.quote_command` returns a quoted command line, suitable for use as an argument to `Sys.command`, `Unix.system`, and the `Unix.open_process` functions.\nHowever on Windows certain characters weren\u0027t properly escaped.\n\n`Unix.create_process` can invoke `.bat` or `.cmd` programs on Windows, and certain characters were accepted that cannot be quoted safely.\n\n## Fix\n\n`Filename.quote_command` has been updated to correctly quote arguments.\n`Unix.create_process*` has been updated to reject arguments that cannot be safely quoted by raising `Failure`:\n\u003e if the program [prog] is a [.bat] or [.cmd]\n\u003e script and either [prog] or [args] contain characters that cannot be\n\u003e securely passed to a script, such as [\" | \u0026 , ; \u003c = \u003e ^ % \"].\n\u003e If you really need to pass these characters to a script, consider\n\u003e using {!Unix.system} instead.\n\n## Am I affected?\n\nIf you use `Filename.quote_command` on Windows with user supplied arguments.\nIf you use `Unix.create_process*` or `Unix.open_process*` on Windows with `.bat` or `.cmd` programs, and user supplied arguments.\n\n## Timeline\n\n- 2026-08-24: vulnerability was found\n- 2026-08-27: forwarded report to security@ocaml.org\n- 2029-09-05: fix merged to trunk",
"id": "OSEC-2026-24",
"modified": "2026-10-23T21:30:00Z",
"published": "2026-10-23T21:30:00Z",
"references": [],
"schema_version": "1.7.4",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Multiple issues in command quoting on Windows"
}
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