How severe is CVE-2024-5699?

CVE-2024-5699 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2024-5699 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-5699?

CVE-2024-5699 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-5699?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2024-5699 have an EU (EUVD) identifier?

Yes. CVE-2024-5699 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-46871.

When was CVE-2024-5699 published?

CVE-2024-5699 was published on 2024-06-11 and last updated on 2026-06-17.

CVE-2024-5699

CVE-2024-5699 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-178.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-46871
Weakness: CWE-178
Affected product: Mozilla Firefox
Published: 2024-06-11
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2024-5699?: 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.
How severe is CVE-2024-5699?: CVE-2024-5699 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2024-5699 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-5699?: CVE-2024-5699 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-5699?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2024-5699 have an EU (EUVD) identifier?: Yes. CVE-2024-5699 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-46871.
When was CVE-2024-5699 published?: CVE-2024-5699 was published on 2024-06-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

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