CVE-2026-3833

EUVD-2026-26403
A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) or `rfc822Name` (email) constraints within `excludedSubtrees` or `permittedSubtrees`. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 43%
Affected Products (NVD)
VendorProductVersion
gnugnutls
-
redhathardened_images
-
redhatopenshift_container_platform
4.0
redhatenterprise_linux
6.0
redhatenterprise_linux
7.0
redhatenterprise_linux
8.0
redhatenterprise_linux
9.0
redhatenterprise_linux
10.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
gnutls28
bookworm
3.7.9-2+deb12u7
fixed
bookworm (security)
3.7.9-2+deb12u7
fixed
bullseye
vulnerable
bullseye (security)
3.7.1-5+deb11u10
fixed
forky
3.8.13-1
fixed
sid
3.8.13-1
fixed
trixie
3.8.9-3+deb13u4
fixed
trixie (security)
3.8.9-3+deb13u4
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
gnutls28
bionic
Fixed 3.5.18-1ubuntu1.6+esm3
released
focal
Fixed 3.6.13-2ubuntu1.12+esm2
released
jammy
Fixed 3.7.3-4ubuntu1.9
released
noble
Fixed 3.8.3-1.1ubuntu3.6
released
questing
Fixed 3.8.9-3ubuntu2.2
released
resolute
Fixed 3.8.12-2ubuntu1.1
released
xenial
Fixed 3.4.10-4ubuntu1.9+esm3
released
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
gnutls
suse enterprise desktop 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise sap 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise server 12 SP3
3.3.27-3.21.1
fixed
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP6
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP7
3.8.3-150600.4.20.1
fixed
gnutls-guile
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
libgnutls-devel
suse enterprise desktop 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise sap 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP6
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP7
3.8.3-150600.4.20.1
fixed
libgnutls-openssl27
suse enterprise server 12 SP3
3.3.27-3.21.1
fixed
libgnutls28
suse enterprise server 12 SP3
3.3.27-3.21.1
fixed
libgnutls28-32bit
suse enterprise server 12 SP3
3.3.27-3.21.1
fixed
libgnutls30
suse enterprise desktop 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise sap 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP6
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP7
3.8.3-150600.4.20.1
fixed
libgnutls30-32bit
suse enterprise desktop 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise sap 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP6
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP7
3.8.3-150600.4.20.1
fixed
libgnutls30-hmac
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
libgnutls30-hmac-32bit
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
libgnutlsxx-devel
suse enterprise desktop 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise sap 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP6
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP7
3.8.3-150600.4.20.1
fixed
libgnutlsxx28
suse enterprise server 15 SP4
3.7.3-150400.4.59.1
fixed
suse enterprise server 15 SP5
3.7.3-150400.4.59.1
fixed
libgnutlsxx30
suse enterprise desktop 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise sap 15 SP7
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP6
3.8.3-150600.4.20.1
fixed
suse enterprise server 15 SP7
3.8.3-150600.4.20.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
gnutls
RHEL 8
0:3.6.16-8.el8_10.6
fixed
RHEL 8.4 AUS
0:3.6.14-10.el8_4.1
fixed
RHEL 8.6 AUS
0:3.6.16-5.el8_6.5
fixed
RHEL 8.8 E4S
0:3.6.16-7.el8_8.4
fixed
RHEL 8.8 TUS
0:3.6.16-7.el8_8.4
fixed
RHEL 9
0:3.8.10-4.el9_8
fixed
gnutls-c
RHEL 8
0:3.6.16-8.el8_10.6
fixed
RHEL 8.4 AUS
0:3.6.14-10.el8_4.1
fixed
RHEL 8.6 AUS
0:3.6.16-5.el8_6.5
fixed
RHEL 8.8 E4S
0:3.6.16-7.el8_8.4
fixed
RHEL 8.8 TUS
0:3.6.16-7.el8_8.4
fixed
RHEL 9
0:3.8.10-4.el9_8
fixed
gnutls-dane
RHEL 8
0:3.6.16-8.el8_10.6
fixed
RHEL 8.4 AUS
0:3.6.14-10.el8_4.1
fixed
RHEL 8.6 AUS
0:3.6.16-5.el8_6.5
fixed
RHEL 8.8 E4S
0:3.6.16-7.el8_8.4
fixed
RHEL 8.8 TUS
0:3.6.16-7.el8_8.4
fixed
RHEL 9
0:3.8.10-4.el9_8
fixed
gnutls-devel
RHEL 8
0:3.6.16-8.el8_10.6
fixed
RHEL 8.4 AUS
0:3.6.14-10.el8_4.1
fixed
RHEL 8.6 AUS
0:3.6.16-5.el8_6.5
fixed
RHEL 8.8 E4S
0:3.6.16-7.el8_8.4
fixed
RHEL 8.8 TUS
0:3.6.16-7.el8_8.4
fixed
RHEL 9
0:3.8.10-4.el9_8
fixed
gnutls-utils
RHEL 8
0:3.6.16-8.el8_10.6
fixed
RHEL 8.4 AUS
0:3.6.14-10.el8_4.1
fixed
RHEL 8.6 AUS
0:3.6.16-5.el8_6.5
fixed
RHEL 8.8 E4S
0:3.6.16-7.el8_8.4
fixed
RHEL 8.8 TUS
0:3.6.16-7.el8_8.4
fixed
RHEL 9
0:3.8.10-4.el9_8
fixed
libtasn1
RHEL 8.4 AUS
0:4.13-3.el8_4.1
fixed
RHEL 8.6 AUS
0:4.13-3.el8_6.2
fixed
RHEL 8.8 E4S
0:4.13-4.el8_8.1
fixed
RHEL 8.8 TUS
0:4.13-4.el8_8.1
fixed
libtasn1-devel
RHEL 8.4 AUS
0:4.13-3.el8_4.1
fixed
RHEL 8.6 AUS
0:4.13-3.el8_6.2
fixed
RHEL 8.8 E4S
0:4.13-4.el8_8.1
fixed
RHEL 8.8 TUS
0:4.13-4.el8_8.1
fixed
libtasn1-tools
RHEL 8.4 AUS
0:4.13-3.el8_4.1
fixed
RHEL 8.6 AUS
0:4.13-3.el8_6.2
fixed
RHEL 8.8 E4S
0:4.13-4.el8_8.1
fixed
RHEL 8.8 TUS
0:4.13-4.el8_8.1
fixed
Amazon Linux logo
Amazon Linux Releases
Amazon Package
Release
gnutls
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-c++
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-c++-debuginfo
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-dane
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-dane-debuginfo
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-debuginfo
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-debugsource
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-devel
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-utils
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
gnutls-utils-debuginfo
Amazon Linux 2023
0:3.8.3-8.amzn2023.0.3
fixed
Common Weakness Enumeration
References
https://access.redhat.com/errata/RHSA-2026:13274
https://access.redhat.com/errata/RHSA-2026:20611
https://access.redhat.com/errata/RHSA-2026:20612
https://access.redhat.com/errata/RHSA-2026:20613
https://access.redhat.com/errata/RHSA-2026:26319
https://access.redhat.com/errata/RHSA-2026:26409
https://access.redhat.com/errata/RHSA-2026:29197
https://access.redhat.com/errata/RHSA-2026:30004
https://access.redhat.com/errata/RHSA-2026:30849
https://access.redhat.com/errata/RHSA-2026:30850
https://access.redhat.com/errata/RHSA-2026:32962
https://access.redhat.com/errata/RHSA-2026:33125
https://access.redhat.com/errata/RHSA-2026:41921
https://access.redhat.com/errata/RHSA-2026:43575
https://access.redhat.com/security/cve/CVE-2026-3833
https://bugzilla.redhat.com/show_bug.cgi?id=2445763
https://gitlab.com/gnutls/gnutls/-/issues/1803
https://gitlab.com/gnutls/gnutls/-/issues/1803