7-Zip XZ Decompression Heap-based Buffer Overflow Remote Code Execution Vulnerability

July 15th, 2026
ZDI-26-444 ZDI-CAN-30169

CVE ID

CVE-2026-14266

CVSS Score

7.0 AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected Vendors

7-Zip

Affected Products

7-Zip

Vulnerability Details

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.

Additional Details

Fixed in 7-Zip 26.02


Disclosure Timeline

  • 2026-06-05 - Vulnerability reported to vendor
  • 2026-07-15 - Coordinated public release of advisory
  • 2026-07-15 - Advisory Updated

Credit

Lunbun LLC (Landon Peng)

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