CVE-2026-34743
XZ Utils: Buffer overflow in lzma_index_append()
Description
XZ Utils provide a general-purpose data-compression library plus command-line tools. Prior to version 5.8.3, if lzma_index_decoder() was used to decode an Index that contained no Records, the resulting lzma_index was left in a state where where a subsequent lzma_index_append() would allocate too little memory, and a buffer overflow would occur. This issue has been patched in version 5.8.3.
No summary for this CVE yet.
CVSS Vector Breakdown
Exploitability
AV:NAttack VectorNetwork
AC:LAttack ComplexityLow
PR:NPrivileges RequiredNone
UI:NUser InteractionNone
Scope
S:UScopeUnchanged
Impact
C:NConfidentialityNone
I:NIntegrityNone
A:LAvailabilityLow
Weaknesses
Affected Products
tukaani
oss-projectaka tukaani xz
tukaani-project
oss-project·FIaka tukaani project, tukaani
ООО «Ред Софт»
commercial·RUaka red soft
Exploitability
Official Patch Available
Attack Graph
Products CVE Techniques Tactics
Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.
MITRE ATT&CK
1 technique Privilege Escalation
References
https://github.com/tukaani-project/xz/commit/c8c22869e780ff57c96b46939c3d79ff99395f87
github.com
https://github.com/tukaani-project/xz/releases/tag/v5.8.3
github.com
https://github.com/tukaani-project/xz/security/advisories/GHSA-x872-m794-cxhv
github.com
and 4 more references View all →
Unlock Complete Vulnerability Intelligence
Get the full picture for CVE-2026-34743 and every CVE in our database. Create a free account — no credit card required.
Create Free AccountPlain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows