CVE-2025-8037

Name: CVE-2025-8037
Creator: NVD / NIST
Published: 2025-07-22T21:15:50.86+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 0.22%

Last modified Jun 17, 2026

CVE-2025-8037 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. Setting a nameless cookie with an equals sign in the value shadowed other cookies. Even if the nameless cookie was set over HTTP and the shadowed cookie included the `Secure` attribute. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

Description

Setting a nameless cookie with an equals sign in the value shadowed other cookies. Even if the nameless cookie was set over HTTP and the shadowed cookie included the `Secure` attribute. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

0.22%

12.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-614

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 140.1
Mozilla	Firefox	< 141.0
Mozilla	Thunderbird	< 140.1
Mozilla	Thunderbird	< 141.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1964767Permissions Required
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

Timeline

Published: Jul 22, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-8037?

How severe is CVE-2025-8037?

CVE-2025-8037 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2025-8037?

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-2025-8037?

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

Scan your code now

Source: NVD / NIST