How severe is CVE-2020-12404?

CVE-2020-12404 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-2020-12404 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-12404?

CVE-2020-12404 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-12404?

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

When was CVE-2020-12404 published?

CVE-2020-12404 was published on 2020-07-09 and last updated on 2026-06-17.

CVE-2020-12404

CVE-2020-12404 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mozilla Firefox
Published: 2020-07-09
Last modified: 2026-06-17

Description

For native-to-JS bridging the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token could leak when used for downloading files. This vulnerability affects Firefox for iOS < 26.

Frequently asked questions

What is CVE-2020-12404?: For native-to-JS bridging the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token could leak when used for downloading files. This vulnerability affects Firefox for iOS < 26.
How severe is CVE-2020-12404?: CVE-2020-12404 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-2020-12404 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-12404?: CVE-2020-12404 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-12404?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-12404 published?: CVE-2020-12404 was published on 2020-07-09 and last updated on 2026-06-17.

References

Affected products (1)

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

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