CVE-2026-34743
xz: XZ Utils: Denial of Service via buffer overflow in index decoding
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 3, 2026
Updated · November 4, 2026
Description
A flaw was found in XZ Utils. When the lzma_index_decoder() function processes an empty index, and a subsequent lzma_index_append() operation is performed, insufficient memory is allocated. This can lead to a buffer overflow, potentially causing a denial of service (DoS) for affected systems.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE-131 · Incorrect Calculation of Buffer Size