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.

CVSS 3.1

6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-25)

CWE

CWE-591

Published

2025-10-14

Modified

2026-10-23

Record from

the NVD, synced 2026-10-24

Affected

• mozilla:firefox
• mozilla:thunderbird

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/
• https://www.mozilla.org/security/advisories/mfsa2025-83/
• https://www.mozilla.org/security/advisories/mfsa2025-84/

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