CVE-2025-1012

Name: CVE-2025-1012
Creator: NVD / NIST
Published: 2025-02-04T14:15:32+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.42%

Last modified Jun 17, 2026

CVE-2025-1012 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.. EPSS estimates a 0.42% chance of exploitation in the next 30 days.

Description

A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.42%

33.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 115.20.0
Mozilla	Firefox	< 135.0
Mozilla	Firefox	>= 128.1.0, < 128.7.0
Mozilla	Thunderbird	< 135.0
Mozilla	Thunderbird	>= 128.0.1, < 128.7.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1939710Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-07/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-08/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-09/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-10/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-11/Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/02/msg00005.html
https://lists.debian.org/debian-lts-announce/2025/02/msg00006.html

Timeline

Published: Feb 4, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-1012?

A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

How severe is CVE-2025-1012?

CVE-2025-1012 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.42% probability of exploitation in the next 30 days.

How do I fix CVE-2025-1012?

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-2025-1012?

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

Scan your code now

Source: NVD / NIST