Vulnerability 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 Score
MEDIUM
Related Weaknesses (CWE)
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
FAQ
What is CVE-2026-117556?
CVE-2026-117556 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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. ...
How severe is CVE-2026-117556?
CVE-2026-117556 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-117556?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.