CVE-2026-117556
zchunk before 1.5.5 Heap Out-of-Bounds Read via read_preface()
- State
- Published
- Severity
- 5.3 Medium
- Published
- Oct 27, 2026
- Updated
- Oct 28, 2026
- Reserved
- Oct 27, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L | VulnCheck |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
zchunkzchunk |
|
References
- GitHub Issue #119issue-tracking
- https://github.com/zchunk/zchunkproduct
- https://github.com/zchunk/zchunk/commit/02b371a64bf98245df97315d07c684a0ca5ea1dfpatch
- zchunk 1.5.5 Release Notesrelease-notes
- https://github.com/zchunk/zchunk/blob/1.5.4/src/lib/header.c#L167technical-description
- VulnCheck Advisory: zchunk before 1.5.5 Heap Out-of-Bounds Read via read_preface()third-party-advisory
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