# CVE-2026-103222: Blosc C-Blosc2 blosclz Decompression blosclz.c blosclz_decompress integer overflow

> An integer overflow in the blosclz decompression function of C-Blosc2 allows remote attackers to cause a denial of service.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-103222, GHSA-c776-5v2h-x5j5, UBUNTU-CVE-2026-103222

## What is CVE-2026-103222?

CVE-2026-103222 is a medium-severity vulnerability in C-Blosc2, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was determined in Blosc C-Blosc2 up to 3.3.2. This impacts the function blosclz_decompress of the file blosc/blosclz.c of the component blosclz Decompression. Executing a manipulation can lead to integer overflow. The attack may be launched remotely. A high complexity level is associated with this attack. The exploitability is said to be difficult. Upgrading to version 3.3.3 will fix this issue. This patch is called fe2964d114d97847f56570a0ab2be2c57ccbeedc. The affected component should be upgraded.

Weakness: CWE-190 (Integer Overflow or Wraparound), CWE-189

## Which versions are affected by CVE-2026-103222?


## How do I fix CVE-2026-103222?

Upgrade to a fixed version.

## Is CVE-2026-103222 being exploited?

There is no known exploitation of CVE-2026-103222 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103222 and fix it if it is affected.

What it is: CVE-2026-103222 is a medium-severity vulnerability in C-Blosc2, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-103222 in the wild and no public exploit code.

Affected product: C-Blosc2. 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-2026-103222/ (Markdown: https://insights.sbomify.com/CVE-2026-103222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103222
- OSV: https://osv.dev/vulnerability/CVE-2026-103222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103222/
Summaries are generated and may contain mistakes; the official description above is the record.