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CVE-2024-9399

21
FAUCET Score

CVE-2024-9399 describes a denial-of-service vulnerability in Firefox and Thunderbird, affecting versions prior to 131 and 128.3 respectively. A specially crafted WebTransport session initiated by a malicious website can crash the browser process. Rated High severity (CVSS 7.5), this vulnerability requires no user interaction and has a high impact on availability. Currently, there is no evidence of active exploitation, public exploit code, or significant community discussion, indicating a low immediate threat.

Impacted Technologies

VendorProductVersion(s)CPE
< 128.3.0CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
>= 129.0, < 131.0CPE matchmatch criteria
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
< 128.3.0CPE matchmatch criteria
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
>= 129.0, < 131.0CPE matchmatch criteria
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.49%
Probability of exploitation in next 30 days
EPSS Percentile
39.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0049 is in the 17th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (30)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9.2 Extended Update SupportFixed in: thunderbird-0:128.3.0-1.el9_2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7 Extended Lifecycle SupportFixed in: firefox-0:128.3.0-1.el7_9
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: thunderbird-0:128.3.0-1.el8_10
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: firefox-0:128.3.0-1.el8_10
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.2 Advanced Update SupportFixed in: firefox-0:128.3.0-1.el8_2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.2 Advanced Update SupportFixed in: thunderbird-0:128.3.0-1.el8_2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportFixed in: firefox-0:128.3.0-1.el8_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportFixed in: thunderbird-0:128.3.0-1.el8_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Telecommunications Update ServiceFixed in: firefox-0:128.3.0-1.el8_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Telecommunications Update ServiceFixed in: thunderbird-0:128.3.0-1.el8_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Update Services for SAP SolutionsFixed in: firefox-0:128.3.0-1.el8_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Update Services for SAP SolutionsFixed in: thunderbird-0:128.3.0-1.el8_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportFixed in: firefox-0:128.3.0-1.el8_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportFixed in: thunderbird-0:128.3.0-1.el8_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.6 Telecommunications Update ServiceFixed in: firefox-0:128.3.0-1.el8_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.6 Telecommunications Update ServiceFixed in: thunderbird-0:128.3.0-1.el8_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionsFixed in: firefox-0:128.3.0-1.el8_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionsFixed in: thunderbird-0:128.3.0-1.el8_6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.8 Extended Update SupportFixed in: firefox-0:128.3.0-1.el8_8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.8 Extended Update SupportFixed in: thunderbird-0:128.3.1-1.el8_8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: thunderbird-0:128.3.0-1.el9_4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsFixed in: firefox-0:128.3.0-1.el9_0
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsFixed in: thunderbird-0:128.3.0-1.el9_0
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9.2 Extended Update SupportFixed in: firefox-0:128.3.0-1.el9_2
View patch
mozillavendor investigatingvia nvd_reference
View patch
redhatno patchvia redhat_api
Product: Red Hat Enterprise Linux 10Fixed in: firefox
redhatno patchvia redhat_api
Product: Red Hat Enterprise Linux 10Fixed in: thunderbird
redhatno patchvia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: firefox
redhatno patchvia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: firefox-flatpak-container
redhatno patchvia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: thunderbird-flatpak-container

Vendor Advisories (1)

redhatCVE-2024-9399Low

firefox: thunderbird: Specially crafted WebTransport requests could lead to denial of service

Oct 1, 2024

References

bugzilla.mozilla.org / show_bug.cgi
Issue TrackingPermissions Required
mozilla.org / security/advisories/mfsa2024-46
Vendor Advisory
mozilla.org / security/advisories/mfsa2024-47
Vendor Advisory
mozilla.org / security/advisories/mfsa2024-49
Vendor Advisory
mozilla.org / security/advisories/mfsa2024-50
Vendor Advisory