CVE-2026-4700

EUVD-2026-14817
Mitigation bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 6%
Affected Products (NVD)
VendorProductVersion
mozillafirefox_esr
𝑥
< 140.9.0
mozillafirefox
𝑥
< 149.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
firefox
sid
150.0.2-1
fixed
firefox-esr
bookworm
vulnerable
bookworm (security)
140.10.2esr-1~deb12u1
fixed
bullseye
vulnerable
bullseye (security)
140.10.2esr-1~deb11u1
fixed
forky
140.10.1esr-1
fixed
sid
140.10.2esr-1
fixed
trixie
vulnerable
trixie (security)
140.10.2esr-1~deb13u1
fixed
thunderbird
bookworm
vulnerable
bookworm (security)
1:140.10.1esr-1~deb12u1
fixed
bullseye
vulnerable
bullseye (security)
1:140.10.1esr-1~deb11u1
fixed
forky
1:140.10.1esr-1
fixed
sid
1:140.10.1esr-1
fixed
trixie
vulnerable
trixie (security)
1:140.10.1esr-1~deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
firefox
jammy
not-affected
noble
not-affected
questing
not-affected
resolute
not-affected
thunderbird
jammy
needed
noble
not-affected
questing
not-affected
resolute
not-affected
mozjs38
bionic
needs-triage
jammy
dne
noble
dne
questing
dne
resolute
dne
mozjs52
bionic
ignored
focal
ignored
jammy
dne
noble
dne
questing
dne
resolute
dne
mozjs68
focal
ignored
jammy
dne
noble
dne
questing
dne
resolute
dne
mozjs78
jammy
ignored
noble
dne
questing
dne
resolute
dne
mozjs91
jammy
ignored
noble
dne
questing
dne
resolute
dne
mozjs102
jammy
ignored
noble
ignored
questing
dne
resolute
dne
mozjs115
jammy
dne
noble
ignored
questing
dne
resolute
dne
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
MozillaFirefox
suse enterprise desktop 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise server 12 SP3
140.9.0-112.304.2
fixed
suse enterprise server 12 SP5
140.9.0-112.304.2
fixed
suse enterprise server 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.152.225.1
fixed
MozillaFirefox-devel
suse enterprise desktop 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise server 12 SP3
140.9.0-112.304.2
fixed
suse enterprise server 12 SP5
140.9.0-112.304.2
fixed
suse enterprise server 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.152.225.1
fixed
MozillaFirefox-translations-common
suse enterprise desktop 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise server 12 SP3
140.9.0-112.304.2
fixed
suse enterprise server 12 SP5
140.9.0-112.304.2
fixed
suse enterprise server 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.152.225.1
fixed
MozillaFirefox-translations-other
suse enterprise desktop 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP4
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP5
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP6
140.9.0-150200.152.225.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.152.225.1
fixed
MozillaThunderbird
suse enterprise desktop 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise workstation 15 SP7
140.9.0-150200.8.263.1
fixed
MozillaThunderbird-translations-common
suse enterprise desktop 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise workstation 15 SP7
140.9.0-150200.8.263.1
fixed
MozillaThunderbird-translations-other
suse enterprise desktop 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise sap 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise server 15 SP7
140.9.0-150200.8.263.1
fixed
suse enterprise workstation 15 SP7
140.9.0-150200.8.263.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
firefox
RHEL 9
0:140.9.0-1.el9_7
fixed
firefox-x11
RHEL 9
0:140.9.0-1.el9_7
fixed
thunderbird
RHEL 9
0:140.9.0-1.el9_7
fixed
Common Weakness Enumeration
References
https://bugzilla.mozilla.org/show_bug.cgi?id=2003766
https://www.mozilla.org/security/advisories/mfsa2026-20/
https://www.mozilla.org/security/advisories/mfsa2026-22/
https://www.mozilla.org/security/advisories/mfsa2026-23/
https://www.mozilla.org/security/advisories/mfsa2026-24/