---
title: "CVE-2026-109395: Ning compress-lzf - Out-of-Bounds Read/Write"
description: "Ning compress-lzf < 1.2.0 contains an out-of-bounds memory access vulnerability caused by improper validation of back-references and literal runs in UnsafeChunkDecoder, letting attackers leak JVM heap memory or crash the JVM, exploit requires crafted LZF streams."
url: https://panop.io/threat-heartbeat/CVE-2026-109395/
---

# CVE-2026-109395 Ning compress-lzf - Out-of-Bounds Read/Write

Ning compress-lzf < 1.2.0 contains an out-of-bounds memory access vulnerability caused by improper validation of back-references and literal runs in UnsafeChunkDecoder, letting attackers leak JVM heap memory or crash the JVM, exploit requires crafted LZF streams.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-109395)

## Details

Type

Out-of-Bounds Read/Write

Impact

Information Disclosure, Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Published

20 October 2026

Updated

20 October 2026

Weakness

[CWE-125](https://cwe.mitre.org/data/definitions/125.html)

## Vendor fix

Update to version 1.2.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-109395](https://nvd.nist.gov/vuln/detail/CVE-2026-109395)
- [https://github.com/github/securitylab/discussions/970](https://github.com/github/securitylab/discussions/970)
- [https://github.com/ning/compress](https://github.com/ning/compress)
- [https://github.com/ning/compress/blob/compress-lzf-1.1.3/src/main/java/com/ning/compress/lzf/impl/UnsafeChunkDecoder.java#L104](https://github.com/ning/compress/blob/compress-lzf-1.1.3/src/main/java/com/ning/compress/lzf/impl/UnsafeChunkDecoder.java#L104)
- [https://github.com/ning/compress/commit/06bdc3744a96b736a7118891f403e44c664f108b](https://github.com/ning/compress/commit/06bdc3744a96b736a7118891f403e44c664f108b)
- [https://github.com/ning/compress/pull/68](https://github.com/ning/compress/pull/68)
- [https://www.vulncheck.com/advisories/ning-compress-lzf-before-1.2.0-out-of-bounds-memory-access-via-unsafechunkdecoder](https://www.vulncheck.com/advisories/ning-compress-lzf-before-1.2.0-out-of-bounds-memory-access-via-unsafechunkdecoder)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)