CVE-2026-104086

7-Zip < 26.03 SquashFS Uninitialized Memory Disclosure via UID/GID Table

CVSS score

6.8

EPSS probability

—

Risk score

0.7

Published

4 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

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Vulnerability description

CVE AI research

The stored explanation is shown at once; refreshing evaluates the sources again.

DayBreach AI Explanation

Verified against sources

CVE-2026-104086: 7-Zip SquashFS Memory Disclosure

Sources read

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

CVE-2026-104086 is an uninitialized memory disclosure vulnerability in the SquashFS v4 archive handler of 7-Zip before 26.03. Listing or extracting a crafted archive can leak heap memory contents.

Why does it matter?

This vulnerability leads to heap memory leaks that can expose sensitive process memory contents. The patch status remains unverified in official sources.

What should be done?

Follow vendor advisories
Check official channels for updates

Chain of evidence and sources2 verified claims

CVE-2026-104086, 26.03 öncesi 7-Zip sürümlerindeki SquashFS v4 arşiv işleyicisini etkiler.

S0 · daybreach-canonical S1 · nvd

Zafiyet, kpidUserId ve kpidGroupId özellikleri aracılığıyla başlatılmamış yığın belleği sızıntısına neden olur.

S0 · daybreach-canonical S1 · nvd

Show the technical text from the sources

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 vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CWE: CWE-908

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-104086 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	7-zip	7-zip	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
6.8	CVSS V4_0	MEDIUM	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N	CVE CNA
6.8	CVSS V40	MEDIUM	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD
5.5	CVSS V3_1	MEDIUM	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N	CVE CNA
5.5	CVSS V31	MEDIUM	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N	NVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

cvelist

Fixed Release

Open source

reference

Fixed Release

Open source

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Apply the official update named in the evidence only to the matching product and version.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-104086 is associated with the following CWEs:

CWE-908: Common Weakness Enumeration Entry CWE-908

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-104086 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureYerel erişim

PermissionsGerekmiyor

User—

Official Sources and Advisories

Fixed Releasepatch Project Webpagevendor-advisory VulnCheck Advisory: 7-Zip < 26.03 SquashFS Uninitialized Memory Disclosure via UID/GID Tablevendor-advisory

CVSS Vector Radar Chart

6.8 / 10

Vulnerability Scoring Details

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredNone required

User InteractionP

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)P

Availability (Erişilebilirlik)None

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

7-zip

Weakness Type (CWE & CAPEC)

CWE-908

Similar Vulnerabilities

7.8

CVE-2026-14266

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