CVE-2026-117556
Description
A flaw was found in zchunk. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by tricking an application into processing a specially crafted file. Improper boundary checking during file header parsing causes the program to read beyond the allocated memory buffer, leading to an application crash.
Statement
This vulnerability is rated as having a Low severity impact because exploitation requires a victim or automated process to handle an untrusted file, with consequences limited to an unexpected termination of the decompression process. In Red Hat environments, zchunk is typically invoked during package metadata operations against trusted, cryptographically verified repositories, which drastically limits exposure to malicious input. Because the memory violation affects only transient user-space execution and does not provide opportunities for system compromise or unauthorized access, the overall risk to supported systems is minimal.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | N/A | 4.3 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
