CVE-2025-1017

Name: CVE-2025-1017
Creator: NVD / NIST
Published: 2025-02-04T14:15:32.6+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2025-1017 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.53%

41.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 128.7.0
Mozilla	Firefox	< 135.0
Mozilla	Thunderbird	>= 128.0.1, < 128.7.0
Mozilla	Thunderbird	>= 131.0, < 135.0

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1926256%2C1935984%2C1935471Broken Link
https://www.mozilla.org/security/advisories/mfsa2025-07/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/msg00006.html

Timeline

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

Frequently Asked Questions

What is CVE-2025-1017?

How severe is CVE-2025-1017?

CVE-2025-1017 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2025-1017?

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-2025-1017?

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

Scan your code now

Source: NVD / NIST