CVE-2026-104086
7-Zip < 26.03 SquashFS Uninitialized Memory Disclosure via UID/GID Table
CVSS Score
5.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-908 |
| Vendor | 7-zip |
| Product | 7-zip |
| Published | Oct 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
7-Zip / 7-Zip
0 < 26.03
References
Credits
Dhanush Arvind