Out-of-bounds Read Affecting zchunk package, versions *


Severity

Recommended
low

Based on Debian security rating.

Threat Intelligence

EPSS
0.33% (26th percentile)

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  • Snyk IDSNYK-DEBIAN14-ZCHUNK-21786220
  • published29 Oct 2026
  • disclosed27 Oct 2026

Introduced: 27 Oct 2026

NewCVE-2026-117556  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

There is no fixed version for Debian:14 zchunk.

NVD Description

Note: Versions mentioned in the description apply only to the upstream zchunk package and not the zchunk package as distributed by Debian. See How to fix? for Debian:14 relevant fixed versions and status.

zchunk before 1.5.5 contains a heap out-of-bounds read vulnerability in read_preface() in src/lib/header.c that passes the total header length instead of remaining bytes to compint parsing functions. Attackers can supply a crafted .zck file whose header ends inside a compressed integer, causing reads past the heap header buffer and crashing the application.

CVSS Base Scores

version 3.1