How severe is CVE-2024-6603?

CVE-2024-6603 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2024-6603 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-6603?

CVE-2024-6603 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-6603?

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

Does CVE-2024-6603 have an EU (EUVD) identifier?

Yes. CVE-2024-6603 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-47665.

When was CVE-2024-6603 published?

CVE-2024-6603 was published on 2024-07-09 and last updated on 2026-06-17.

CVE-2024-6603

CVE-2024-6603 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 7.4. 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-823.

Key facts

Severity: High (CVSS 3.x base score 7.4)
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-47665
Weakness: CWE-823
Affected product: Mozilla Firefox
Published: 2024-07-09
Last modified: 2026-06-17

Description

In an out-of-memory scenario an allocation could fail but free would have been called on the pointer afterwards leading to memory corruption. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13, and Thunderbird < 128.

Frequently asked questions

What is CVE-2024-6603?: In an out-of-memory scenario an allocation could fail but free would have been called on the pointer afterwards leading to memory corruption. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13, and Thunderbird < 128.
How severe is CVE-2024-6603?: CVE-2024-6603 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2024-6603 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-6603?: CVE-2024-6603 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-6603?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2024-6603 have an EU (EUVD) identifier?: Yes. CVE-2024-6603 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-47665.
When was CVE-2024-6603 published?: CVE-2024-6603 was published on 2024-07-09 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

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