How severe is CVE-2020-6830?

CVE-2020-6830 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-6830 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-6830?

CVE-2020-6830 affects Mozilla Firefox Mobile. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-6830?

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.

When was CVE-2020-6830 published?

CVE-2020-6830 was published on 2020-05-26 and last updated on 2026-08-19.

CVE-2020-6830

CVE-2020-6830 is a high-severity vulnerability in Mozilla Firefox Mobile with a CVSS 3.x base score of 7.5. 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-200.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Mozilla Firefox Mobile
Published: 2020-05-26
Last modified: 2026-08-19

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 was being used for JS-to-native also, but it isn't needed in this case, and its usage was also leaking this token. This vulnerability affects Firefox for iOS < 25.

Frequently asked questions

What is CVE-2020-6830?: 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 was being used for JS-to-native also, but it isn't needed in this case, and its usage was also leaking this token. This vulnerability affects Firefox for iOS < 25.
How severe is CVE-2020-6830?: CVE-2020-6830 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-6830 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-6830?: CVE-2020-6830 affects Mozilla Firefox Mobile. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-6830?: 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.
When was CVE-2020-6830 published?: CVE-2020-6830 was published on 2020-05-26 and last updated on 2026-08-19.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox_mobile:*:*:*:*:*:iphone_os:*:*

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