# CVE-2026-34353: Integer overflow in OCaml

> An integer overflow in OCaml's Bigarray.reshape allows attackers to read arbitrary memory when processing untrusted data.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 27 Mar 2026
- **Also known as:** AZL-81104, DEBIAN-CVE-2026-34353, GHSA-6p45-jv22-32gp, OESA-2026-1889, OESA-2026-1890, OESA-2026-1891, OESA-2026-1892, OESA-2026-1893, OSEC-2026-04, UBUNTU-CVE-2026-34353

## What is CVE-2026-34353?

CVE-2026-34353 is a medium-severity vulnerability in OCaml, published on 27 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In OCaml through 4.14.3, Bigarray.reshape allows an integer overflow, and resultant reading of arbitrary memory, when untrusted data is processed.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-34353?

It affects 1 product.


Products: Ocaml Ocaml.

## How do I fix CVE-2026-34353?

Upgrade to a fixed version.

## Is CVE-2026-34353 being exploited?

There is no known exploitation of CVE-2026-34353 in the wild and no public exploit code.

## Other vulnerabilities in OCaml

- [CVE-2018-9838](https://insights.sbomify.com/CVE-2018-9838/): Integer overflow in n/a (critical 9.8)
- [CVE-2017-9772](https://insights.sbomify.com/CVE-2017-9772/): Privilege escalation in n/a (critical 9.8)
- [CVE-2026-28364](https://insights.sbomify.com/CVE-2026-28364/): Memory corruption in OCaml (high 7.9)
- [CVE-2017-9779](https://insights.sbomify.com/CVE-2017-9779/): Other in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34353 and fix it if it is affected.

What it is: CVE-2026-34353 is a medium-severity vulnerability in OCaml, published on 27 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34353 in the wild and no public exploit code.

Affected product: OCaml. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34353/ (Markdown: https://insights.sbomify.com/CVE-2026-34353/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34353
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34353
- OSV: https://osv.dev/vulnerability/CVE-2026-34353

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34353/
Summaries are generated and may contain mistakes; the official description above is the record.