CVE-2026-14266Public exploit

Code execution via XZ chunk heap overflow

Published Jul 29, 2026 · Updated Jul 29, 2026

Heap-based buffer overflow in 7-Zip 26.01 allows remote attackers to execute code by inducing a user to open crafted XZ data. The XZ decompressor processes crafted chunked data in a manner that overflows a heap buffer during decompression. Exploitation requires user interaction, and successful code runs in the context of the 7-Zip process.

CVSS severity7.0
High
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in 7-Zip 26.01 allows remote attackers to execute code by inducing a user to open crafted XZ data. The XZ decompressor processes crafted chunked data in a manner that overflows a heap buffer during decompression. Exploitation requires user interaction, and successful code runs in the context of the 7-Zip process.

The record

CVE
CVE-2026-14266
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
7-Zip
Product
7-Zip
Classifications
CWE-122, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=26.01

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

7-Zip · 7-Zipversion=26.01

Published CVSS scores

7.0Zero Day InitiativeCVSS:3.0/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1204.002User Execution Malicious File
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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