How severe is CVE-2025-6428?

CVE-2025-6428 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 none, integrity low, and availability none.

Is CVE-2025-6428 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-6428?

CVE-2025-6428 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-6428?

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

Does CVE-2025-6428 have an EU (EUVD) identifier?

Yes. CVE-2025-6428 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-28735.

When was CVE-2025-6428 published?

CVE-2025-6428 was published on 2025-06-24 and last updated on 2026-06-17.

CVE-2025-6428

CVE-2025-6428 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-601.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-28735
Weakness: CWE-601
Affected product: Mozilla Firefox
Published: 2025-06-24
Last modified: 2026-06-17

Description

When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing attacks. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 140.

Frequently asked questions

What is CVE-2025-6428?: When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing attacks. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 140.
How severe is CVE-2025-6428?: CVE-2025-6428 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 none, integrity low, and availability none.
Is CVE-2025-6428 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-6428?: CVE-2025-6428 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-6428?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-6428 have an EU (EUVD) identifier?: Yes. CVE-2025-6428 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-28735.
When was CVE-2025-6428 published?: CVE-2025-6428 was published on 2025-06-24 and last updated on 2026-06-17.

References

Affected products (1)

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

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