RLSA-2026:98486: Moderate: xz security update
XZ Utils is an integrated collection of user-space file compression utilities based on the Lempel-Ziv-Markov chain algorithm (LZMA), which performs lossless data compression. The algorithm provides a high compression ratio while keeping the decompression time short.
Security Fix(es):
xz: XZ Utils: Denial of Service via buffer overflow in index decoding (CVE-2026-34743)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
rocky-linux/xzto a version that resolves this vulnerability.Fixed in 0:5.2.5-8.el9_8.1
Event History
Frequently Asked Questions
What is the practical impact of this issue?
The issue can cause a denial of service through a buffer overflow while decoding XZ index data. The provided CVSS vector indicates network-reachable exploitation requires no privileges or user interaction, with availability impact only.
Which systems should be prioritized for remediation?
Prioritize Rocky Linux systems that have the xz package installed and process untrusted or remotely supplied XZ-compressed data. Systems that do not decode XZ data have no indicated exposure path in the provided advisory.
What can be done if the update cannot be applied immediately?
Limit or avoid decoding untrusted XZ-compressed files until the security update can be installed. Restrict network-facing services or workflows that automatically process attacker-supplied XZ data.