CVE-2026-104086

7-Zip before 26.03 contains an uninitialized memory disclosure vulnerability in the SquashFS v4 archive handler (SquashfsHandler.cpp) that allows attackers to leak heap memory by crafting a malicious archive where the superblock’s no_ids field is set so that the final metadata block’s expected size is miscomputed and bypasses the size validation check. By listing or extracting the crafted archive, attackers can cause the application to return uninitialized heap memory as the kpidUserId and kpidGroupId properties, exposing potentially sensitive process memory contents to the user.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://7-zip.org/
https://sourceforge.net/p/sevenzip/discussion/45797/thread/db6922e1d0/
https://www.vulncheck.com/advisories/7-zip-squashfs-uninitialized-memory-disclosure-via-uid-gid-table

Configurations

No configuration.

History

14 Oct 2026, 14:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-14 14:17

Updated : 2026-10-19 20:17

NVD link : CVE-2026-104086

Mitre link : CVE-2026-104086

CVE.ORG link : CVE-2026-104086

JSON object : View

Products Affected

No product.

CWE

CWE-908

Use of Uninitialized Resource

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