8.8
HIGH
CVE-2025-8040
Mozilla Firefox and Thunderbird Memory Corruption Vulnerability
Description

Memory safety bugs present in Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. 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 affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.

INFO

Published Date :

July 22, 2025, 9:15 p.m.

Last Modified :

July 30, 2025, 5:15 p.m.

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

2.8
Affected Products

The following products are affected by CVE-2025-8040 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mozilla firefox
2 Mozilla firefox_esr
3 Mozilla thunderbird
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-8040.

URL Resource
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1975058%2C1975998
https://www.mozilla.org/security/advisories/mfsa2025-56/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-59/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-61/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-63/ Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-8040 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-8040 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Jul. 30, 2025

    Action Type Old Value New Value
    Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=1975058%2C1975998
    Removed Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=1975058%2C1975058%2C1975998%2C1975998
    Removed Reference Type https://bugzilla.mozilla.org/buglist.cgi?bug_id=1975058%2C1975058%2C1975998%2C1975998 Types: Broken Link
  • Initial Analysis by [email protected]

    Jul. 28, 2025

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 141.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* versions up to (excluding) 141.0 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions up to (excluding) 140.1 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* versions up to (excluding) 140.1
    Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/buglist.cgi?bug_id=1975058%2C1975058%2C1975998%2C1975998 Types: Broken Link
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2025-56/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2025-59/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2025-61/ Types: Vendor Advisory
    Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2025-63/ Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 23, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    Added CWE CWE-119
  • New CVE Received by [email protected]

    Jul. 22, 2025

    Action Type Old Value New Value
    Added Description Memory safety bugs present in Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. 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 affects Firefox < 141, Firefox ESR < 140.1, Thunderbird < 141, and Thunderbird < 140.1.
    Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=1975058%2C1975058%2C1975998%2C1975998
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-56/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-59/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-61/
    Added Reference https://www.mozilla.org/security/advisories/mfsa2025-63/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS31 - Vulnerability Scoring System
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