ALSA-2026:89749: Moderate: xz security update

Q: Which installed packages should be checked for exposure?

The advisory applies to almalinux/xz, almalinux/xz-devel, almalinux/xz-libs, and almalinux/xz-lzma-compat. Systems with any of these packages installed should be reviewed for the security update.

Q: What impact is identified for this issue?

The issue is identified as a denial of service caused by a buffer overflow during XZ index decoding. The provided information does not describe additional impacts or exploitation prerequisites.

Published Oct 26, 2026

Updated

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

4 affected componentsFixes available

almalinux/xz<5.2.5-8.el9_8.1

5.2.5-8.el9_8.1

almalinux/xz-devel<5.2.5-8.el9_8.1

5.2.5-8.el9_8.1

almalinux/xz-libs<5.2.5-8.el9_8.1

5.2.5-8.el9_8.1

almalinux/xz-lzma-compat<5.2.5-8.el9_8.1

5.2.5-8.el9_8.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade almalinux/xz to a version that resolves this vulnerability.
Fixed in 5.2.5-8.el9_8.1
Upgrade
Upgrade almalinux/xz-devel to a version that resolves this vulnerability.
Fixed in 5.2.5-8.el9_8.1
Upgrade
Upgrade almalinux/xz-libs to a version that resolves this vulnerability.
Fixed in 5.2.5-8.el9_8.1
Upgrade
Upgrade almalinux/xz-lzma-compat to a version that resolves this vulnerability.
Fixed in 5.2.5-8.el9_8.1

Event History

Oct 26, 2026

Advisory Published

via OSV·12:00 AM

Data Sourced

via OSV·12:00 AM

DescriptionAffected Software

Child vulnerabilities

Contains the following vulnerabilities.

CVE-2026-34743

Frequently Asked Questions

Which installed packages should be checked for exposure?

The advisory applies to almalinux/xz, almalinux/xz-devel, almalinux/xz-libs, and almalinux/xz-lzma-compat. Systems with any of these packages installed should be reviewed for the security update.

What impact is identified for this issue?

The issue is identified as a denial of service caused by a buffer overflow during XZ index decoding. The provided information does not describe additional impacts or exploitation prerequisites.

ALSA-2026:89749: Moderate: xz security update

Affected Software

Remediation

Event History

Child vulnerabilities

Frequently Asked Questions

Which installed packages should be checked for exposure?

What impact is identified for this issue?

Company

Resources

Contact

Frequently Asked Questions

Which installed packages should be checked for exposure?

What impact is identified for this issue?