CVE-2024-9399
A website configured to initiate a specially crafted WebTransport session could crash the Firefox process leading to a denial of service condition.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.50%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A website configured to initiate a specially crafted WebTransport session could crash the Firefox process leading to a denial of service condition. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.50% probability · 42th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-404
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1907726Issue Tracking, Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2024-46/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2024-47/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2024-49/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2024-50/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.