CVE-2026-347431.7LowCWE-122

CVE-2026-34743: XZ Utils: Buffer overflow in lzma_index_append()

tukaani-project · xz

Affected: tukaani-project xz · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days

45th percentile

050100

Higher than 45% of scored CVEs

1.7LowCVSS 4.0

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

tukaani-project · xz< 5.8.3

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Heap-based Buffer Overflow · Memory Corruption
Vendor: tukaani-project
Published: April 2026
Band: Unlikely (under 1%), April 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-34743 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.