# CVE-2026-90559 — xerial snappy-java

> As of 2026-09-12, CVE-2026-90559 is a HIGH-severity vulnerability in xerial snappy-java, CVSS v3.1 7.5. No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-90559 as of 2026-09-12; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-09-12

## What is CVE-2026-90559?

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.

The record classifies CVE-2026-90559 under weakness class [CWE-787](https://intel.threadlinqs.com/cwe/CWE-787). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 23 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **CVSS v4.0 base score:** 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`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-12

## Is CVE-2026-90559 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **xerial**: snappy-java

## How to fix CVE-2026-90559

No vendor patch reference has been recorded for CVE-2026-90559 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-90559

No threat campaign in the Threadlinqs corpus currently references CVE-2026-90559, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org. Last verified by Threadlinqs on 2026-09-14.

**Technical analysis**

- [github.com — technical description](https://github.com/xerial/snappy-java/blob/v1.1.10.8/src/main/java/org/xerial/snappy/Snappy.java#L561)

**Third-party advisory**

- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/snappy-java-through-1.1.10.8-out-of-bounds-write-via-uncompress)

**Issue tracking and product pages**

- [github.com — issue tracking](https://github.com/xerial/snappy-java/issues/728)
- [github.com — product](https://github.com/xerial/snappy-java)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-90559
Full detection coverage and IOCs for threats exploiting CVE-2026-90559 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp