CVE-2026-2783

Name: CVE-2026-2783
Creator: NVD / NIST
Published: 2026-02-24T14:16:26.747+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.29%

Last modified Jun 17, 2026

CVE-2026-2783 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.. EPSS estimates a 0.29% chance of exploitation in the next 30 days.

Description

Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.29%

20.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 140.8.0
Mozilla	Firefox	< 148.0
Mozilla	Thunderbird	< 140.8.0
Mozilla	Thunderbird	< 148.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2010943Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-13/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-15/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-16/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-17/Vendor Advisory

Timeline

Published: Feb 24, 2026
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-2783?

Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

How severe is CVE-2026-2783?

CVE-2026-2783 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2026-2783?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-2783?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST