CVE-2026-8959

Published: Mag 19, 2026 Last Modified: Mag 20, 2026
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 9,6
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: required
Scope: changed
Confidentiality: high
Integrity: high
Availability: high

Description

AI Translation Available

Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0006
Percentile
0,2th
Updated

Single Data Point

Only one EPSS measurement is available for this CVE. Trend analysis requires multiple data points over time.

20

Improper Input Validation

Stable
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Confidentiality Integrity
Potential Impacts:
Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Read Memory Read Files Or Directories Modify Memory Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies: AI/ML
Likelihood of Exploit: High
View CWE Details
119

Improper Restriction of Operations within the Bounds of a Memory Buffer

Stable
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability
Potential Impacts:
Execute Unauthorized Code Or Commands Modify Memory Read Memory Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory)
Applicable Platforms
Languages: Memory-Unsafe, C, C++, Assembly
Likelihood of Exploit: High
View CWE Details
693

Protection Mechanism Failure

Draft
Abstraction: Pillar Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control
Potential Impacts:
Bypass Protection Mechanism
Applicable Platforms
Technologies: Not Technology-Specific, ICS/OT
View CWE Details
Application

Thunderbird by Mozilla

Product Information
Vendor Mozilla
Product Thunderbird
Version Range Affected
To 140.11 (exclusive)
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Firefox by Mozilla

Product Information
Vendor Mozilla
Product Firefox
Version Range Affected
To 140.11.0 (exclusive)
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Firefox by Mozilla

Product Information
Vendor Mozilla
Product Firefox
Version Range Affected
To 151.0.0 (exclusive)
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Thunderbird by Mozilla

Product Information
Vendor Mozilla
Product Thunderbird
Version Range Affected
To 151.0.0 (exclusive)
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://bugzilla.mozilla.org/show_bug.cgi?id=2034754
https://bugzilla.mozilla.org/show_bug.cgi?id=2034754
https://www.mozilla.org/security/advisories/mfsa2026-46/
https://www.mozilla.org/security/advisories/mfsa2026-46/
https://www.mozilla.org/security/advisories/mfsa2026-48/
https://www.mozilla.org/security/advisories/mfsa2026-48/
https://www.mozilla.org/security/advisories/mfsa2026-50/
https://www.mozilla.org/security/advisories/mfsa2026-50/
https://www.mozilla.org/security/advisories/mfsa2026-51/
https://www.mozilla.org/security/advisories/mfsa2026-51/