# CVE-2026-90559: snappy-java through 1.1.10.8 Out-of-Bounds Write via uncompress

> Attackers can cause JVM termination by supplying compressed data that overflows the destination buffer during decompression in snappy-java.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Sep 2026
- **Updated:** 8 Oct 2026
- **Also known as:** CLEANSTART-2026-DF81862, CLEANSTART-2026-FZ14074, CLEANSTART-2026-GD87503, CLEANSTART-2026-VP40557, ECHO-49f5-2d75-9004, GHSA-mrhq-xxpp-qf7j

## What is CVE-2026-90559?

CVE-2026-90559 is a high-severity memory corruption vulnerability in xerial snappy-java, published on 12 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

snappy-java through 1.1.10.8 contains an out-of-bounds write vulnerability in Snappy.uncompress(ByteBuffer, ByteBuffer) because destination buffer capacity is never validated against decompressed size. Attackers can supply valid compressed data that decompresses larger than the destination buffer, causing writes past buffer boundaries and JVM termination.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-90559?


## How do I fix CVE-2026-90559?

Upgrade to a fixed version.

## Is CVE-2026-90559 being exploited?

There is no known exploitation of CVE-2026-90559 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90559 and fix it if it is affected.

What it is: CVE-2026-90559 is a high-severity memory corruption vulnerability in xerial snappy-java, published on 12 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-2026-90559 in the wild and no public exploit code.

Affected product: xerial snappy-java. 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-2026-90559/ (Markdown: https://insights.sbomify.com/CVE-2026-90559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90559
- OSV: https://osv.dev/vulnerability/CVE-2026-90559

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90559/
Summaries are generated and may contain mistakes; the official description above is the record.