Distribution advisory
This page covers CVE-2026-34743 as tracked by Ubuntu, for the package xz-utils. The fix is available in version 5.8.1-1ubuntu0.1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability low.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: None — an unauthenticated stranger can try it.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: None.
- Integrity impact: None.
- Availability impact: Low — limited, and the attacker does not choose what is affected.
Weakness class
UBUNTU-CVE-2026-34743 is classified as CWE-122: Heap-based Buffer Overflow. A write past the end of a heap allocation corrupts allocator metadata or neighbouring objects.
Affected software
UBUNTU-CVE-2026-34743 is recorded against 1 package.
- xz-utils (fixed in 5.8.1-1ubuntu0.1)
Timeline and source
Published on 2 April 2026 and last revised on 2 June 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
tukaani.org (Report)
ubuntu.com (Advisory)
Other advisories for this package
xz-utils has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-122: Heap-based Buffer Overflow) in other software:
