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.
Does this matter?
Lower severity and no EPSS score yet. Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- No score yet
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Source
- disclosure@vulncheck.com
References
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.