CVE-2026-12291

EUVD-2026-37082
Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mozillaCNA
8.8 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 32.13%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
Red HatRed Hat Enterprise Linux 10
0:140.12.0-1.el10_2 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support
0:140.12.0-1.el10_0 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Support
0:140.12.0-1.el7_9 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8
0:140.12.0-1.el8_10 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
0:140.12.0-1.el8_4 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
0:140.12.0-1.el8_4 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
0:140.12.0-1.el8_6 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
0:140.12.0-1.el8_6 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service
0:140.12.0-1.el8_8 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions
0:140.12.0-1.el8_8 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 9
0:140.12.0-1.el9_8 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutions
0:140.12.0-1.el9_2 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutions
0:140.12.0-1.el9_4 ≤
𝑥
< *
ADP
Red HatRed Hat Enterprise Linux 9.6 Extended Update Support
0:140.12.0-1.el9_6 ≤
𝑥
< *
ADP
mozillafirefox
𝑥
< 152.0.0
CNA
mozillafirefox_esr
𝑥
< 115.37.0
CNA
mozillafirefox_esr
128.0 ≤
𝑥
< 140.12.0
CNA
mozillathunderbird
𝑥
< 152.0.0
CNA
mozillathunderbird_esr
𝑥
< 140.12.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
firefox
sid
158.0.1-1
fixed
firefox-esr
bookworm
140.12.0esr-1~deb12u1
fixed
bookworm (security)
153.5.1esr-1~deb12u1
fixed
forky
153.5.0esr-1
fixed
sid
153.5.1esr-1
fixed
trixie
140.15.0esr-1~deb13u1
fixed
trixie (security)
153.5.1esr-1~deb13u1
fixed
thunderbird
bookworm
1:140.12.0esr-1~deb12u1
fixed
bookworm (security)
1:140.17.0esr-1~deb12u1
fixed
forky
1:153.5.0esr-1
fixed
sid
1:153.5.1esr-1
fixed
trixie
1:140.12.0esr-1~deb13u1
fixed
trixie (security)
1:140.17.0esr-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
140.12.0-150200.152.245.1
fixed
suse enterprise sap 12 SP5
140.12.0-112.321.1
fixed
suse enterprise sap 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise server 12 SP3
140.12.0-112.321.1
fixed
suse enterprise server 12 SP5
140.12.0-112.321.1
fixed
suse enterprise server 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.152.245.1
fixed
MozillaFirefox-devel
suse enterprise desktop 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise sap 12 SP5
140.12.0-112.321.1
fixed
suse enterprise sap 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise server 12 SP3
140.12.0-112.321.1
fixed
suse enterprise server 12 SP5
140.12.0-112.321.1
fixed
suse enterprise server 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.152.245.1
fixed
MozillaFirefox-translations-common
suse enterprise desktop 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise sap 12 SP5
140.12.0-112.321.1
fixed
suse enterprise sap 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise server 12 SP3
140.12.0-112.321.1
fixed
suse enterprise server 12 SP5
140.12.0-112.321.1
fixed
suse enterprise server 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.152.245.1
fixed
MozillaFirefox-translations-other
suse enterprise desktop 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP4
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP5
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP6
140.12.0-150200.152.245.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.152.245.1
fixed
MozillaThunderbird
suse enterprise desktop 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise workstation 15 SP7
140.12.0-150200.8.277.1
fixed
MozillaThunderbird-translations-common
suse enterprise desktop 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise workstation 15 SP7
140.12.0-150200.8.277.1
fixed
MozillaThunderbird-translations-other
suse enterprise desktop 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise sap 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise server 15 SP7
140.12.0-150200.8.277.1
fixed
suse enterprise workstation 15 SP7
140.12.0-150200.8.277.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
firefox
RHEL 9
0:140.12.0-1.el9_8
fixed
firefox-x11
RHEL 9
0:140.12.0-1.el9_8
fixed
thunderbird
RHEL 9
0:140.12.0-1.el9_8
fixed
Amazon Linux logo
Amazon Linux Releases
Amazon Package
Release
firefox
Amazon Linux 2023
0:140.12.0-1.amzn2023.0.1
fixed
firefox-debuginfo
Amazon Linux 2023
0:140.12.0-1.amzn2023.0.1
fixed
firefox-debugsource
Amazon Linux 2023
0:140.12.0-1.amzn2023.0.1
fixed
Common Weakness Enumeration
References
https://bugzilla.mozilla.org/show_bug.cgi?id=2036929
https://www.mozilla.org/security/advisories/mfsa2026-57/
https://www.mozilla.org/security/advisories/mfsa2026-58/
https://www.mozilla.org/security/advisories/mfsa2026-59/
https://www.mozilla.org/security/advisories/mfsa2026-60/
https://www.mozilla.org/security/advisories/mfsa2026-61/
https://access.redhat.com/errata/RHSA-2026:27717
https://access.redhat.com/errata/RHSA-2026:27733
https://access.redhat.com/errata/RHSA-2026:27734
https://access.redhat.com/errata/RHSA-2026:29940
https://access.redhat.com/errata/RHSA-2026:30846
https://access.redhat.com/errata/RHSA-2026:33445
https://access.redhat.com/errata/RHSA-2026:36100
https://access.redhat.com/errata/RHSA-2026:36101
https://access.redhat.com/errata/RHSA-2026:36102
https://access.redhat.com/errata/RHSA-2026:36103
https://access.redhat.com/errata/RHSA-2026:37210
https://access.redhat.com/errata/RHSA-2026:37391
https://access.redhat.com/errata/RHSA-2026:38506
https://access.redhat.com/errata/RHSA-2026:38750
https://access.redhat.com/errata/RHSA-2026:38751
https://access.redhat.com/errata/RHSA-2026:38753
https://access.redhat.com/errata/RHSA-2026:39011
https://access.redhat.com/errata/RHSA-2026:39141
https://access.redhat.com/errata/RHSA-2026:39142
https://access.redhat.com/errata/RHSA-2026:39428
https://access.redhat.com/errata/RHSA-2026:39706
https://access.redhat.com/security/cve/CVE-2026-12291
https://bugzilla.redhat.com/show_bug.cgi?id=2489244
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12291.json