CVE-2026-48103Public exploitNetwork attack vector

Archive-processing crash via WIM securityId off-by-one read

Published Jun 5, 2026 · Updated Jun 5, 2026

Out-of-bounds read in 7-Zip 9.34 through 26.00 allows attackers to crash archive processing via crafted WIM metadata. CHandler::GetSecurity accepts securityId equal to the final SecurOffsets record index, then reads SecurOffsets[securityId + 1] past the heap allocation. Opening the archive in the Windows GUI or listing it with technical details triggers the read; the demonstrated consequence is a crash, with no write primitive or attacker-visible disclosure.

CVSS severity4.3
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in 7-Zip 9.34 through 26.00 allows attackers to crash archive processing via crafted WIM metadata. CHandler::GetSecurity accepts securityId equal to the final SecurOffsets record index, then reads SecurOffsets[securityId + 1] past the heap allocation. Opening the archive in the Windows GUI or listing it with technical details triggers the read; the demonstrated consequence is a crash, with no write primitive or attacker-visible disclosure.

The record

CVE
CVE-2026-48103
Published
Jun 5, 2026
Updated
Jun 5, 2026
Vendor
7-Zip
Product
7-Zip
Classifications
CWE-125
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 5, 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=>= 9.34, < 26.01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

7-Zip · 7-Zipversion=>= 9.34, < 26.01

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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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