# CVE-2026-87736: Memory corruption in mirage-crypto-ec

> An out-of-bounds read in the mirage-crypto-ec library allows attackers to read memory or cause crashes when processing compressed EC public keys.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-87736, GHSA-x37h-cx7x-wm76, OSEC-2026-15, UBUNTU-CVE-2026-87736

## What is CVE-2026-87736?

CVE-2026-87736 is a medium-severity memory corruption vulnerability in OCaml mirage-crypto-ec, published on 9 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An issue was discovered in the mirage-crypto-ec package before 2.3.0 for OCaml. There is an EC public key out-of-bounds read for compressed points.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-87736?


## How do I fix CVE-2026-87736?

Upgrade to a fixed version.

## Is CVE-2026-87736 being exploited?

There is no known exploitation of CVE-2026-87736 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87736 and fix it if it is affected.

What it is: CVE-2026-87736 is a medium-severity memory corruption vulnerability in OCaml mirage-crypto-ec, published on 9 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-87736 in the wild and no public exploit code.

Affected product: OCaml mirage-crypto-ec. 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-2026-87736/ (Markdown: https://insights.sbomify.com/CVE-2026-87736/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87736
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87736
- OSV: https://osv.dev/vulnerability/CVE-2026-87736

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-87736/
Summaries are generated and may contain mistakes; the official description above is the record.