Heap-based Buffer Overflow Affecting xz package, versions <5.8.3-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.06% (19th percentile)

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  • Snyk IDSNYK-ALPINE320-XZ-16336347
  • published1 May 2026
  • disclosed2 Apr 2026

Introduced: 2 Apr 2026

CVE-2026-34743  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Alpine:3.20 xz to version 5.8.3-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream xz package and not the xz package as distributed by Alpine. See How to fix? for Alpine:3.20 relevant fixed versions and status.

XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, if lzma_index_decoder() was used to decode an Index that contained no Records, the resulting lzma_index was left in a state where where a subsequent lzma_index_append() would allocate too little memory, and a buffer overflow would occur. This issue has been patched in version 5.8.3.

CVSS Base Scores

version 3.1