What is CVE-2023-25743?

A lack of in app notification for entering fullscreen mode could have lead to a malicious website spoofing browser chrome. *This bug only affects Firefox Focus. Other versions of Firefox are unaffected.*. This vulnerability affects Firefox < 110 and Firefox ESR < 102.8.

How severe is CVE-2023-25743?

CVE-2023-25743 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 none, integrity high, and availability none.

Is CVE-2023-25743 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-25743?

CVE-2023-25743 affects Mozilla Firefox Focus. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-25743?

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-2023-25743 published?

CVE-2023-25743 was published on 2023-06-02 and last updated on 2026-06-17.

CVE-2023-25743

Q: How severe is CVE-2023-25743?

CVE-2023-25743 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 none, integrity high, and availability none.

Q: Is CVE-2023-25743 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

Q: What products are affected by CVE-2023-25743?

CVE-2023-25743 affects Mozilla Firefox Focus. See the affected-products list for the exact vulnerable versions.

Q: How do I fix CVE-2023-25743?

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.

Q: When was CVE-2023-25743 published?

CVE-2023-25743 was published on 2023-06-02 and last updated on 2026-06-17.

CVE-2023-25743 is a high-severity vulnerability in Mozilla Firefox Focus 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-290.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-290
Affected product: Mozilla Firefox Focus
Published: 2023-06-02
Last modified: 2026-06-17

Description

A lack of in app notification for entering fullscreen mode could have lead to a malicious website spoofing browser chrome.<br>*This bug only affects Firefox Focus. Other versions of Firefox are unaffected.*. This vulnerability affects Firefox < 110 and Firefox ESR < 102.8.

Frequently asked questions

What is CVE-2023-25743?: A lack of in app notification for entering fullscreen mode could have lead to a malicious website spoofing browser chrome.<br>*This bug only affects Firefox Focus. Other versions of Firefox are unaffected.*. This vulnerability affects Firefox < 110 and Firefox ESR < 102.8.
How severe is CVE-2023-25743?: CVE-2023-25743 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 none, integrity high, and availability none.
Is CVE-2023-25743 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-25743?: CVE-2023-25743 affects Mozilla Firefox Focus. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-25743?: 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-2023-25743 published?: CVE-2023-25743 was published on 2023-06-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox_focus:-:*:*:*:*:*:*:*

More vulnerabilities in Mozilla Firefox Focus

CVE-2025-55031 — Critical (CVSS 9.8): Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport. An…
CVE-2022-26486 — Critical (CVSS 9.6): An unexpected message in the WebGPU IPC framework could lead to a use-after-free and exploitable sandbox escape. We…
CVE-2023-29534 — Critical (CVSS 9.1): Different techniques existed to obscure the fullscreen notification in Firefox and Focus for Android. These could have…
CVE-2022-26485 — High (CVSS 8.8): Removing an XSLT parameter during processing could have lead to an exploitable use-after-free. We have had reports of…
CVE-2024-1563 — High (CVSS 8.1): An attacker could have executed unauthorized scripts on top origin sites using a JavaScript URI when opening an…
CVE-2026-8945 — High (CVSS 7.5): Sandbox escape in Firefox and Firefox Focus for Android. This vulnerability was fixed in Firefox 151.

All CVEs affecting Mozilla Firefox Focus →

Other CWE-290 vulnerabilities

CVE-2026-48567 — Critical (CVSS 10.0): Authentication bypass by spoofing in Azure HorizonDB allows an unauthorized attacker to elevate privileges over a…
CVE-2026-6213 — Critical (CVSS 10.0): A vulnerability in Remote Spark SparkView before build 1122 allows an attacker to bypasses the local connection check…
CVE-2026-39858 — Critical (CVSS 10.0): Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high…
CVE-2025-66570 — Critical (CVSS 10.0): cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.27.0, a vulnerability…
CVE-2025-34063 — Critical (CVSS 10.0): A cryptographic authentication bypass vulnerability exists in OneLogin AD Connector prior to 6.1.5 due to the exposure…
CVE-2023-22814 — Critical (CVSS 10.0): An authentication bypass issue via spoofing was discovered in the token-based authentication mechanism that could allow…

Browse all CWE-290 vulnerabilities →