Medium · CVSS 6.8CVE-2026-104086

7-Zip < 26.03 SquashFS Uninitialized Memory Disclosure via UID/GID TableCVE-2026-104086

Answer in brief

CVE-2026-104086 records a Medium severity (CVSS 6.8) vulnerability in 7-Zip < 26.03 SquashFS Uninitialized Memory Disclosure via UID/GID Table. The current sources do not mark it as known exploited. The current feed maps 7-Zip/7-Zip (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 14, 2026Updated Oct 14, 2026Source checked Oct 14, 2026First seen by HOL Oct 14, 2026Material review Oct 14, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 6.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps 7-Zip/7-Zip (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
7-Zip/7-Zipgeneric	>=0 <26.03	26.03

Recommended response

Check inventory. Check lockfiles and deployed manifests for 7-Zip/7-Zip.
Review the reported fix. Update 7-Zip/7-Zip to 26.03 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 14, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.