A website configured to initiate a specially crafted WebTransport session could crash the Firefox process leading to a denial of service…

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.

Scores

EPSS (exploitation in 30 days)

0.50% · top 57% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.

Weakness

• Specially crafted WebTransport requests could lead to denial of service
• CWE-404 Improper Resource Shutdown or Release (opens in a new tab)All about CWE-404 and its CVEs

Affected products

• Mozilla · Firefox

  • affected unspecified – < 131

• Mozilla · Firefox ESR

  • affected unspecified – < 128.3

• Mozilla · Thunderbird

  • affected unspecified – < 128.3

• Mozilla · Thunderbird

  • affected unspecified – < 131

References (5)

• https://bugzilla.mozilla.org/show_bug.cgi?id=1907726 (opens in a new tab)
• https://www.mozilla.org/security/advisories/mfsa2024-46/ (opens in a new tab)
• https://www.mozilla.org/security/advisories/mfsa2024-47/ (opens in a new tab)
• https://www.mozilla.org/security/advisories/mfsa2024-49/ (opens in a new tab)
• https://www.mozilla.org/security/advisories/mfsa2024-50/ (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2024-9399](https://trackcve.app/badge/CVE-2024-9399.svg)](https://trackcve.app/cve/CVE-2024-9399)

Record last updated 14 Mar 2025, 15:39 UTC.