CVE-2025-11711: firefox — Fix

Description

There was a way to change the value of JavaScript Object properties that were supposed to be non-writeable. This vulnerability was fixed in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.

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CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Weakness Type (CWE)

CWE-591 CWE-591

Affected Products

Vendor	Product	Versions
mozilla	firefox	< 115.29.0
mozilla	firefox	< 144.0
mozilla	firefox	116.0 — 140.4.0
mozilla	thunderbird	< 140.4.0
mozilla	thunderbird	141.0 — 144.0

References

Advisories & Patches

https://www.mozilla.org/security/advisories/mfsa2025-81/ https://www.mozilla.org/security/advisories/mfsa2025-82/ https://www.mozilla.org/security/advisories/mfsa2025-83/ https://www.mozilla.org/security/advisories/mfsa2025-84/ https://www.mozilla.org/security/advisories/mfsa2025-85/

Other References

https://bugzilla.mozilla.org/show_bug.cgi?id=1989978 https://lists.debian.org/debian-lts-announce/2025/10/msg00015.html https://lists.debian.org/debian-lts-announce/2025/10/msg00031.html

Frequently Asked Questions

What is CVE-2025-11711? +

There was a way to change the value of JavaScript Object properties that were supposed to be non-writeable. This vulnerability was fixed in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2025-11711? +

CVE-2025-11711 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-11711? +

CVE-2025-11711 affects products from mozilla, specifically: firefox, thunderbird. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-11711? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.