CVE-2024-5699

Name: CVE-2024-5699
Creator: NVD / NIST
Published: 2024-06-11T13:15:51.333+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.77%

Last modified Jun 17, 2026

CVE-2024-5699 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In violation of spec, cookie prefixes such as `__Secure` were being ignored if they were not correctly capitalized - by spec they should be checked with a case-insensitive comparison. This could have resulted in the browser not correctly honoring the behaviors specified by the prefix. EPSS estimates a 0.77% chance of exploitation in the next 30 days.

Description

In violation of spec, cookie prefixes such as `__Secure` were being ignored if they were not correctly capitalized - by spec they should be checked with a case-insensitive comparison. This could have resulted in the browser not correctly honoring the behaviors specified by the prefix. This vulnerability affects Firefox < 127.

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

0.77%

51.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-178

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 127.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1891349Exploit, Issue Tracking
https://www.mozilla.org/security/advisories/mfsa2024-25/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1891349Exploit, Issue Tracking
https://www.mozilla.org/security/advisories/mfsa2024-25/Vendor Advisory

Timeline

Published: Jun 11, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-5699?

How severe is CVE-2024-5699?

CVE-2024-5699 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.77% probability of exploitation in the next 30 days.

How do I fix CVE-2024-5699?

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-2024-5699?

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

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Source: NVD / NIST