CVE-2026-48104Public exploitNetwork attack vector

Heap disclosure and crash via sparse index reads

Published Jun 5, 2026 · Updated Jun 5, 2026

Out-of-bounds reads in the SquashFS handler in 7-Zip 9.18 through 26.00 allow attackers to disclose heap data or crash 7-Zip via crafted images. The _blockToNode array reserves entries for every metadata block but populates only boundary-crossing entries, so OpenDir passes uninitialized entries selected by RootInode-derived indexes to an unchecked binary search over _nodesPos. Heap layout determines whether the chained read exposes data or dereferences a wild pointer; opening a crafted SquashFS image is the only required interaction.

CVSS severity4.2
Medium
EPSS probability0.18%
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 reads in the SquashFS handler in 7-Zip 9.18 through 26.00 allow attackers to disclose heap data or crash 7-Zip via crafted images. The _blockToNode array reserves entries for every metadata block but populates only boundary-crossing entries, so OpenDir passes uninitialized entries selected by RootInode-derived indexes to an unchecked binary search over _nodesPos. Heap layout determines whether the chained read exposes data or dereferences a wild pointer; opening a crafted SquashFS image is the only required interaction.

The record

CVE
CVE-2026-48104
Published
Jun 5, 2026
Updated
Jun 5, 2026
Vendor
7-Zip
Product
7-Zip
Classifications
CWE-908, CWE-125, T1204.002
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=>= 9.18, < 26.01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

7-Zip · 7-Zipversion=>= 9.18, < 26.01

Published CVSS scores

4.2GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
CWE-125Out-of-bounds Read
T1204.002User Execution: Malicious File

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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