# CVE-2026-122330: Blosc c-blosc2 before 3.5.0 Divide-by-Zero via blosc2_schunk_get_slice_buffer()


- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 5 Nov 2026
- **Updated:** 5 Nov 2026
- **Also known as:** AZL-112694, DEBIAN-CVE-2026-122330, GHSA-99fx-294r-j6xw, UBUNTU-CVE-2026-122330

## What is CVE-2026-122330?

CVE-2026-122330 is a medium-severity vulnerability in c-blosc2, published on 5 Nov 2026. 

### Official description

Blosc c-blosc2 before 3.5.0 contains a divide-by-zero vulnerability in blosc2_schunk_get_slice_buffer() in blosc/schunk.c that allows attackers to crash applications by supplying crafted frames with unchecked zero chunksize or blocksize values. Attackers can provide a malicious Blosc2 frame opened via blosc2_schunk_open() or blosc2_schunk_from_buffer() and read as a slice, raising SIGFPE and terminating the process.

Weakness: CWE-369 (Divide By Zero)

## Which versions are affected by CVE-2026-122330?


## How do I fix CVE-2026-122330?

No fix has been published for CVE-2026-122330 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-122330 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-122330 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-122330 and fix it if it is affected.

What it is: CVE-2026-122330 is a medium-severity vulnerability in c-blosc2, published on 5 Nov 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-122330 exists.

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-2026-122330/ (Markdown: https://insights.sbomify.com/CVE-2026-122330/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-122330
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-122330
- OSV: https://osv.dev/vulnerability/CVE-2026-122330

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-122330/
Summaries are generated and may contain mistakes; the official description above is the record.