CVE-2026-14266: 7-zip Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-14266 is a high (CVSS 7.8) Heap-based Buffer Overflow vulnerability in 7-zip. EPSS estimates a 0.74% chance of exploitation in the next 30 days, higher than 54.1% of scored vulnerabilities.

Timeline

1. 29-07-2026
   PublishedVulnerability first disclosed.
2. 30-07-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().