CVE-2026-117556

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 v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/zchunk/zchunk
https://github.com/zchunk/zchunk/blob/1.5.4/src/lib/header.c#L167
https://github.com/zchunk/zchunk/commit/02b371a64bf98245df97315d07c684a0ca5ea1df
https://github.com/zchunk/zchunk/issues/119
https://github.com/zchunk/zchunk/releases/tag/1.5.5
https://www.vulncheck.com/advisories/zchunk-before-1.5.5-heap-out-of-bounds-read-via-read-preface

Configurations

No configuration.

History

27 Oct 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-27 14:16

Updated : 2026-10-28 17:18

NVD link : CVE-2026-117556

Mitre link : CVE-2026-117556

CVE.ORG link : CVE-2026-117556

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

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