How severe is CVE-2020-15668?

CVE-2020-15668 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2020-15668 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15668?

CVE-2020-15668 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-15668?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-15668 published?

CVE-2020-15668 was published on 2020-10-01 and last updated on 2026-08-19.

CVE-2020-15668

CVE-2020-15668 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 4.3. 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-667.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-667
Affected product: Mozilla Firefox
Published: 2020-10-01
Last modified: 2026-08-19

Description

A lock was missing when accessing a data structure and importing certificate information into the trust database. This vulnerability affects Firefox < 80 and Firefox for Android < 80.

Frequently asked questions

What is CVE-2020-15668?: A lock was missing when accessing a data structure and importing certificate information into the trust database. This vulnerability affects Firefox < 80 and Firefox for Android < 80.
How severe is CVE-2020-15668?: CVE-2020-15668 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2020-15668 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15668?: CVE-2020-15668 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-15668?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-15668 published?: CVE-2020-15668 was published on 2020-10-01 and last updated on 2026-08-19.

References

Affected products (2)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:-:*:*
cpe:2.3:a:mozilla:firefox_mobile:*:*:*:*:*:android:*:*

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