CVE-2025-2817

Name: CVE-2025-2817
Creator: NVD / NIST
Published: 2025-04-29T14:15:32.22+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 0.52%

Last modified Jun 17, 2026

CVE-2025-2817 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. EPSS estimates a 0.52% chance of exploitation in the next 30 days.

Description

Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations on paths controlled by a non-privileged user and enabling privilege escalation. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

0.52%

40.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 115.23.0
Mozilla	Firefox	< 138.0
Mozilla	Firefox	>= 116.0, < 128.10.0
Mozilla	Thunderbird	< 128.10.0
Mozilla	Thunderbird	>= 129.0, < 138.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1917536Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-28/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-29/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-30/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-31/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-32/Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/05/msg00022.html

Timeline

Published: Apr 29, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-2817?

How severe is CVE-2025-2817?

CVE-2025-2817 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.52% probability of exploitation in the next 30 days.

How do I fix CVE-2025-2817?

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-2025-2817?

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

Scan your code now

Source: NVD / NIST