CVE-2025-14324 - Vulnerability Details

- JIT miscompilation in the JavaScript Engine: JIT component

Description

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 146, Firefox ESR 115.31, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.

Published: 2025-12-09

Score: 9.8 Critical

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

JIT miscompilation in the JavaScript engine’s JIT component can cause the browser or email client to execute incorrect code paths. The flaw is rated with a CVSS score of 9.8, indicating that an attacker who can trigger the miscompilation may gain arbitrary code execution privileges, compromising system confidentiality, integrity, and availability.

Affected Systems

Mozilla Firefox versions earlier than 146 and ESR builds earlier than 115.31 or 140.6, as well as Mozilla Thunderbird earlier than 146 and ESR builds earlier than 140.6, are vulnerable. The impacted products include the standard and Enterprise Support Release (ESR) editions of Firefox and Thunderbird.

Risk and Exploitability

Because the vulnerability is tied to the JavaScript engine, exploitation likely requires delivery of crafted JavaScript code – either via a malicious web page or an email containing executable scripts. The EPSS score is below 1 %, suggesting that known exploits are rare or still immature. The vulnerability is not listed in the CISA KEV catalog, but its high CVSS rating and the ability to achieve remote code execution mean that timely patching is essential.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Mozilla

Firefox

affected

Version	Status	Constraints
`115.31`	unaffected	≤ 115.*
`140.6`	unaffected	≤ 140.*
`146`	unaffected	≤ *

Mozilla

Thunderbird

affected

Version	Status	Constraints
`140.6`	unaffected	≤ 140.*
`146`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:a:mozilla:firefox:::::esr:::*
	cpe:2.3:a:mozilla:firefox:::::-:::*
	cpe:2.3:a:mozilla:firefox:::::esr:::*
	cpe:2.3:a:mozilla:thunderbird:::::esr:::*
	cpe:2.3:a:mozilla:thunderbird:::::-:::*

No data.

Vendor	Product	Confidence	Versions
Mozilla	Firefox	—	—
Mozilla	Firefox Esr	—	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Update all affected installations of Firefox and Thunderbird to the patched releases (Firefox 146 or newer, ESR 115.31 or 140.6; Thunderbird 146 or newer, ESR 140.6).
If an immediate update cannot be applied, schedule a forced upgrade through the organization’s software distribution system to ensure all endpoints receive the fix as soon as possible.
As a temporary protective measure, limit the execution of JavaScript in untrusted contexts—such as disabling JavaScript in the email client for unknown senders or enforcing strict content‑security policies for web content already in use.

Generated by OpenCVE AI on April 20, 2026 at 17:37 UTC.

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-4401-1	firefox-esr security update
Debian DLA	DLA-4405-1	thunderbird security update
Debian DSA	DSA-6078-1	firefox-esr security update
Debian DSA	DSA-6081-1	thunderbird security update
Ubuntu USN	USN-7991-1	Thunderbird vulnerabilities

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00051.

Exploitation none

Automatable yes

Technical Impact total

References

Link	Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=1996840
https://nvd.nist.gov/vuln/detail/CVE-2025-14324
https://www.cve.org/CVERecord?id=CVE-2025-14324
https://www.mozilla.org/security/advisories/mfsa2025-92/
https://www.mozilla.org/security/advisories/mfsa2025-93/
https://www.mozilla.org/security/advisories/mfsa2025-94/
https://www.mozilla.org/security/advisories/mfsa2025-94/#CVE-2025-14324
https://www.mozilla.org/security/advisories/mfsa2025-95/
https://www.mozilla.org/security/advisories/mfsa2025-96/

History

Mon, 13 Apr 2026 15:00:00 +0000

Type	Values Removed	Values Added
Description	JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 146, Firefox ESR < 115.31, Firefox ESR < 140.6, Thunderbird < 146, and Thunderbird < 140.6.	JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 146, Firefox ESR 115.31, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.

Thu, 11 Dec 2025 20:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-94
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Wed, 10 Dec 2025 20:45:00 +0000

Type	Values Removed	Values Added
First Time appeared		Mozilla thunderbird
Weaknesses		NVD-CWE-noinfo
CPEs		cpe:2.3:a:mozilla:firefox:::::-:::* cpe:2.3:a:mozilla:firefox:::::esr:::* cpe:2.3:a:mozilla:thunderbird:::::-:::* cpe:2.3:a:mozilla:thunderbird:::::esr:::*
Vendors & Products		Mozilla thunderbird
Metrics	cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}`	cvssV3_1 `{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}`

Wed, 10 Dec 2025 18:00:00 +0000

Type	Values Removed	Values Added
First Time appeared		Mozilla Mozilla firefox Mozilla firefox Esr
Vendors & Products		Mozilla Mozilla firefox Mozilla firefox Esr

Wed, 10 Dec 2025 14:45:00 +0000

Type	Values Removed	Values Added
Description	JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 146, Firefox ESR < 115.31, and Firefox ESR < 140.6.	JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 146, Firefox ESR < 115.31, Firefox ESR < 140.6, Thunderbird < 146, and Thunderbird < 140.6.
References		https://www.mozilla.org/security/advisories/mfsa2025-95/ https://www.mozilla.org/security/advisories/mfsa2025-96/

Wed, 10 Dec 2025 00:15:00 +0000

Type	Values Removed	Values Added
References		https://nvd.nist.gov/vuln/detail/CVE-2025-14324 https://www.cve.org/CVERecord?id=CVE-2025-14324 https://www.mozilla.org/security/advisories/mfsa2025-94/#CVE-2025-14324
Metrics	threat_severity `None`	cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}` threat_severity `Important`

Tue, 09 Dec 2025 13:45:00 +0000

Type	Values Removed	Values Added
Description		JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 146, Firefox ESR < 115.31, and Firefox ESR < 140.6.
Title		JIT miscompilation in the JavaScript Engine: JIT component
References		https://bugzilla.mozilla.org/show_bug.cgi?id=1996840 https://www.mozilla.org/security/advisories/mfsa2025-92/ https://www.mozilla.org/security/advisories/mfsa2025-93/ https://www.mozilla.org/security/advisories/mfsa2025-94/

Subscriptions

Mozilla Firefox Firefox Esr Thunderbird

MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2025-12-09T13:37:57.533Z

Updated: 2026-04-13T14:25:33.489Z

Reserved: 2025-12-09T13:37:56.958Z

Link: CVE-2025-14324

Vulnrichment

Updated: 2025-12-11T20:03:02.945Z

NVD

Status : Modified

Published: 2025-12-09T16:17:39.890

Modified: 2026-04-13T15:16:45.403

Link: CVE-2025-14324

Redhat

Severity : Important

Publid Date: 2025-12-09T13:37:57Z

Links: CVE-2025-14324 - Bugzilla

OpenCVE Enrichment

Updated: 2026-04-20T17:45:12Z

Weaknesses

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

Exploitation none

Automatable yes

Technical Impact total

Subscriptions

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