// For flags

CVE-2025-9181

thunderbird: firefox: Uninitialized memory in the JavaScript Engine component

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

Uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 142, Firefox ESR < 128.14, Firefox ESR < 140.2, Thunderbird < 142, Thunderbird < 128.14, and Thunderbird < 140.2.

A flaw was found in Thunderbird and Firefox. The Mozilla Foundation's Security Advisory describes the following issue: Uninitialized memory in the JavaScript Engine component.

Multiple security issues have been found in the Mozilla Firefox web browser, which could potentially result in the execution of arbitrary code, sandbox escape or bypass of the same-origin policy. For the oldstable distribution (bookworm), these problems have been fixed in version 128.14.0esr-1~deb12u1. For the stable distribution (trixie), these problems have been fixed in version 128.14.0esr-1~deb13u1.

*Credits: Irvan Kurniawan
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-08-19 CVE Reserved
  • 2025-08-19 CVE Published
  • 2025-08-20 CVE Updated
  • 2025-08-25 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-457: Use of Uninitialized Variable
  • CWE-665: Improper Initialization
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mozilla
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 Firefox
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*-
Affected
Mozilla
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 Firefox Esr
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*-
Affected
Mozilla
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 Thunderbird
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*-
Affected
Canonical
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 Ubuntu Linux
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*-
Affected
Centos
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 Centos
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Affected
Debian
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 Debian Linux
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Affected
Fedoraproject
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 Fedora
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Affected
Redhat
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 Enterprise Linux
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Affected
Slackware
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 Slackware Linux
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Affected