How severe is CVE-2025-11720?

CVE-2025-11720 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2025-11720 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-11720?

CVE-2025-11720 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-11720?

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-2025-11720 have an EU (EUVD) identifier?

Yes. CVE-2025-11720 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34194.

When was CVE-2025-11720 published?

CVE-2025-11720 was published on 2025-10-14 and last updated on 2026-06-17.

CVE-2025-11720

CVE-2025-11720 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 8.1. 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-451.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-34194
Weakness: CWE-451
Affected product: Mozilla Firefox
Published: 2025-10-14
Last modified: 2026-06-17

Description

The Firefox and Firefox Focus UI for the Android custom tab feature only showed the "site" that was loaded, not the full hostname. User supplied content hosted on a subdomain of a site could have been used to fool a user into thinking it was content from a different subdomain of that site. This vulnerability was fixed in Firefox 144.

Frequently asked questions

What is CVE-2025-11720?: The Firefox and Firefox Focus UI for the Android custom tab feature only showed the "site" that was loaded, not the full hostname. User supplied content hosted on a subdomain of a site could have been used to fool a user into thinking it was content from a different subdomain of that site. This vulnerability was fixed in Firefox 144.
How severe is CVE-2025-11720?: CVE-2025-11720 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2025-11720 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-11720?: CVE-2025-11720 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-11720?: 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-2025-11720 have an EU (EUVD) identifier?: Yes. CVE-2025-11720 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34194.
When was CVE-2025-11720 published?: CVE-2025-11720 was published on 2025-10-14 and last updated on 2026-06-17.

References

Affected products (1)

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

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