How severe is CVE-2024-8383?

CVE-2024-8383 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-2024-8383 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-8383?

CVE-2024-8383 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-8383?

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-2024-8383 have an EU (EUVD) identifier?

Yes. CVE-2024-8383 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-49139.

When was CVE-2024-8383 published?

CVE-2024-8383 was published on 2024-09-03 and last updated on 2026-06-17.

CVE-2024-8383

CVE-2024-8383 is a high-severity vulnerability in Mozilla Firefox 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-1188.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-49139
Weakness: CWE-1188
Affected product: Mozilla Firefox
Published: 2024-09-03
Last modified: 2026-06-17

Description

Firefox normally asks for confirmation before asking the operating system to find an application to handle a scheme that the browser does not support. It did not ask before doing so for the Usenet-related schemes news: and snews:. Since most operating systems don't have a trusted newsreader installed by default, an unscrupulous program that the user downloaded could register itself as a handler. The website that served the application download could then launch that application at will. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Firefox ESR < 115.15.

Frequently asked questions

What is CVE-2024-8383?: Firefox normally asks for confirmation before asking the operating system to find an application to handle a scheme that the browser does not support. It did not ask before doing so for the Usenet-related schemes news: and snews:. Since most operating systems don't have a trusted newsreader installed by default, an unscrupulous program that the user downloaded could register itself as a handler. The website that served the application download could then launch that application at will. This vulnerability affects Firefox < 130, Firefox ESR < 128.2, and Firefox ESR < 115.15.
How severe is CVE-2024-8383?: CVE-2024-8383 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-2024-8383 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-8383?: CVE-2024-8383 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-8383?: 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-2024-8383 have an EU (EUVD) identifier?: Yes. CVE-2024-8383 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-49139.
When was CVE-2024-8383 published?: CVE-2024-8383 was published on 2024-09-03 and last updated on 2026-06-17.

References

Affected products (2)

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

More vulnerabilities in Mozilla Firefox

CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…

All CVEs affecting Mozilla Firefox →

Other CWE-1188 (Insecure Default Initialization of Resource) vulnerabilities

CVE-2026-31957 — Critical (CVSS 10.0): Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. From 3.0.0 to before 3.1.0, if…
CVE-2025-41672 — Critical (CVSS 10.0): A remote unauthenticated attacker may use default certificates to generate JWT Tokens and gain full access to the tool…
CVE-2024-0001 — Critical (CVSS 10.0): A condition exists in FlashArray Purity whereby a local account intended for initial array configuration remains active…
CVE-2024-2912 — Critical (CVSS 10.0): An insecure deserialization vulnerability exists in the BentoML framework, allowing remote code execution (RCE) by…
CVE-2021-34795 — Critical (CVSS 10.0): Multiple vulnerabilities in the web-based management interface of the Cisco Catalyst Passive Optical Network (PON)…
CVE-2017-7964 — Critical (CVSS 10.0): Zyxel WRE6505 devices have a default TELNET password of 1234 for the root and admin accounts, which makes it easier for…

Browse all CWE-1188 (Insecure Default Initialization of Resource) vulnerabilities →