# CVE-2026-14266 — 7-Zip

> As of 2026-07-30, CVE-2026-14266 is a HIGH-severity vulnerability in 7-Zip, CVSS v3.1 7, EPSS 0.7% (53.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-14266, most recently “CVE-2026-14266: 7-Zip Heap-Based Buffer Overflow in XZ Chunk Handling Enables Arbitrary Code Execution”.

**Last updated:** 2026-07-30

## What is 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.

The record classifies CVE-2026-14266 under weakness class [CWE-122](https://intel.threadlinqs.com/cwe/CWE-122). Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 102 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7 — HIGH (`CVSS:3.0/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.7% probability of exploitation in the next 30 days, higher than 53.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 7.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-29, last modified 2026-07-30

## Is CVE-2026-14266 being exploited?

Weaponised exploit code for CVE-2026-14266 is publicly available. 3 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.

- [4minx/CVE-2026-14266](https://github.com/4minx/CVE-2026-14266) (github)
- [liyuxuan504-byte/CVE-2026-14266](https://github.com/liyuxuan504-byte/CVE-2026-14266) (github)
- [ret2bilibili/CVE-2026-14266](https://github.com/ret2bilibili/CVE-2026-14266) (github)

## Affected products and versions

- **7-Zip**: 7-Zip

## How to fix CVE-2026-14266

No vendor patch reference has been recorded for CVE-2026-14266 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-14266

1 tracked threat in the Threadlinqs corpus references CVE-2026-14266, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-14266: 7-Zip Heap-Based Buffer Overflow in XZ Chunk Handling Enables Arbitrary Code Execution](https://intel.threadlinqs.com/threat/TL-2026-1428) — HIGH · 2026-07-16

## Sources

Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [zerodayinitiative.com — x research advisory](https://www.zerodayinitiative.com/advisories/ZDI-26-444/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-14266
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