JavaScript Property Modification Issue in Mozilla Firefox and Thunderbird
CVE-2025-11711

6.5MEDIUM

Key Information:

Vendor: Mozilla
Status: Firefox; Firefox Esr; Thunderbird
Vendor: CVE Published:; 14 October 2025

What is CVE-2025-11711?

A vulnerability exists in Mozilla's Firefox and Thunderbird that enables attackers to alter the values of JavaScript Object properties that should remain non-writable. This defect may lead to unexpected behavior in applications relying on predictable property states, potentially leading to further security issues.

Affected Version(s)

Firefox < 144

Firefox ESR < 115.29

Firefox ESR < 140.4

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1989978

https://www.mozilla.org/security/advisories/mfsa2025-81/

https://www.mozilla.org/security/advisories/mfsa2025-82/

CVSS V3.1

Score:

6.5

Severity:

MEDIUM

Confidentiality:

None

Integrity:

High

Availability:

None

Attack Vector:

Network

Attack Complexity:

Low

Privileges Required:

None

User Interaction:

Required

Scope:

Unchanged

Timeline

Vulnerability published
Oct 14, 2025
Vulnerability Reserved
Oct 13, 2025

Credit

EntryHi

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