Out-of-bounds write in XZ Utils - #VU148998
Published: September 11, 2026
Vulnerability identifier: #VU148998
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause an invalid memory write.
The vulnerability exists due to improper decoder state handling in the lzma decoder initialization functions when reinitializing a decoder after an allocation failure while processing crafted compressed files. A remote attacker can supply crafted compressed files that cause a decoder to be reinitialized after an allocation failure to cause an invalid memory write.
The final decoded file must specify the same dictionary size as a file decoded before the allocation failure.
Affected software
XZ Utils
Remediation
Install security update from vendor's website.
XZ Utils - update to 5.8.4