OSEC-2026-22
Vulnerability from osv_ocaml – Published: 2026-10-23 21:30 – Updated: 2026-11-06 12:30 – Source websiteANT-2026-6W9NPC2Q mmap dimension product integer overflow
Fix
Use caml_umul_overflow instead of * when multiplying bigarray dimensions, which detects integer overflows and raise Failure.
Negative positions are also rejected by raising Invalid_argument.
Am I affected?
If either the dimensions or the file size in a call to Unix.map_file from your code is user controllable then you are potentially affected.
Score notes
The vulnerability is in a library, and the CVSS score is calculated under worst case assumptions. For an actual application the score will depend on how much an attacker can control the input to this function (if at all).
Timeline
- 2026-08-24: vulnerability was found
- 2026-08-27: forwarded report to security@ocaml.org
- 2026-09-29: fix merged to trunk
{
"affected": [
{
"ecosystem_specific": {
"affected_bindings": [
"Unix.map_file"
],
"opam_constraint": "ocaml {\u003c \"4.14.5\" | \u003e= \"5\" \u0026 \u003c \"5.5.2\"}"
},
"package": {
"ecosystem": "opam",
"name": "ocaml",
"purl": "pkg:opam/ocaml"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.14.5"
}
],
"type": "ECOSYSTEM"
},
{
"events": [
{
"introduced": "5"
},
{
"fixed": "5.5.2"
}
],
"type": "ECOSYSTEM"
}
],
"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",
"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"
]
},
{
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "de57bb4f59c3302260aaeaaa4dfee12695597d25"
}
],
"repo": "https://github.com/ocaml/ocaml",
"type": "GIT"
},
{
"events": [
{
"introduced": "0"
},
{
"fixed": "ff978d2139ba638886c2565f2d86c0ee265840a5"
}
],
"repo": "https://github.com/ocaml/ocaml",
"type": "GIT"
},
{
"events": [
{
"introduced": "0"
},
{
"fixed": "ed4860325cbb11bf05be34fae6ded8019159d182"
}
],
"repo": "https://github.com/ocaml/ocaml",
"type": "GIT"
}
]
}
],
"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": "Edwin T\u00f6r\u00f6k",
"type": "REMEDIATION_REVIEWER"
},
{
"name": "Xavier Leroy",
"type": "REMEDIATION_DEVELOPER"
}
],
"database_specific": {
"cwe": [
"CWE-190"
],
"human_link": "https://github.com/ocaml/security-advisories/tree/main/advisories/2026/OSEC-2026-22.md",
"osv": "https://github.com/ocaml/security-advisories/tree/generated-osv/2026/OSEC-2026-22.json"
},
"details": "ANT-2026-6W9NPC2Q mmap dimension product integer overflow\n\n\n## Fix\n\nUse `caml_umul_overflow` instead of `*` when multiplying bigarray dimensions, which detects integer overflows and raise `Failure`.\nNegative positions are also rejected by raising `Invalid_argument`.\n\n## Am I affected?\n\nIf either the dimensions or the file size in a call to `Unix.map_file` from your code is user controllable then you are potentially affected.\n\n## Score notes\n\nThe vulnerability is in a library, and the CVSS score is calculated [under worst case assumptions](https://www.first.org/cvss/v4.0/user-guide#Assessing-Vulnerabilities-in-Software-Libraries-and-Similar). For an actual application the score will depend on how much an attacker can control the input to this function (if at all).\n\n\n## Timeline\n\n- 2026-08-24: vulnerability was found\n- 2026-08-27: forwarded report to security@ocaml.org\n- 2026-09-29: fix merged to trunk",
"id": "OSEC-2026-22",
"modified": "2026-11-06T12:30:00Z",
"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:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Integer overflow in Unix.map_file"
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.