Buffer overflow in 7-Zip
CVE-2026-14266
7-Zip XZ Decompression Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of XZ chunked data. Crafted XZ-compressed data can trigger an overflow of a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-30169.
Vulnerability class: Buffer Overflow
EPSS: 0.007 (52.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- 7-zip — versions 26.01
Weakness classification (CWE)
Public proof-of-concept exploits
References
- zdi-disclosures@trendmicro.com (x_research-advisory, VDB Entry, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-14266?
- CVE-2026-14266 is a high-severity vulnerability in 7-Zip, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-07-29.
- How severe is CVE-2026-14266?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2026-14266 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.