CVE-2026-12297

Name: CVE-2026-12297
Creator: NVD / NIST
Published: 2026-06-16T13:16:29.927+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.6/10EPSS 0.31%

Last modified Jun 18, 2026

CVE-2026-12297 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

Metrics

CVSS 3.1

9.6/10

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

EPSS Probability

0.31%

23.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 115.37.0
Mozilla	Firefox	< 152.0.0
Mozilla	Firefox	>= 128.0, < 140.12.0
Mozilla	Thunderbird	< 140.12.0
Mozilla	Thunderbird	< 152.0.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2041610Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-57/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-58/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-59/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-60/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-61/Vendor Advisory

Timeline

Published: Jun 16, 2026
Last Modified: Jun 18, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-12297?

How severe is CVE-2026-12297?

CVE-2026-12297 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.

How do I fix CVE-2026-12297?

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-2026-12297?

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

Scan your code now

Source: NVD / NIST