Gnutls: gnutls: certificate validation bypass due to improper handling of uri and srv sans
Published May 26, 2026
7.1
HIGHCVSS 3.1
EPSS 0.49%
Description
A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted certificate that contains Uniform Resource Identifier (URI) or Service (SRV) Subject Alternative Names (SANs). This could cause the certificate validation process to incorrectly fall back to checking DNS hostnames against the Common Name (CN), potentially allowing the attacker to spoof legitimate services or intercept sensitive information.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 6 | affected |
| |||
| Red Hat | Red Hat OpenShift Container Platform 4 | affected |
|
No data.
No data.
Red Hat Discovery 2
discovery/discovery-server-rhel9:1782159791
Fixed · RHSA-2026:29197
Red Hat Discovery 2
discovery/discovery-ui-rhel9:1782166952
Fixed · RHSA-2026:29197
Red Hat Enterprise Linux 10
gnutls-0:3.8.10-4.el10_2
Fixed · RHSA-2026:20613
Red Hat Enterprise Linux 10.0 Extended Update Support
gnutls-0:3.8.9-9.el10_0.19
Fixed · RHSA-2026:26409
Red Hat Enterprise Linux 7 Extended Lifecycle Support
gnutls-0:3.3.29-9.el7_9.2
Fixed · RHSA-2026:43575
Red Hat Enterprise Linux 8
gnutls-0:3.6.16-8.el8_10.6
Fixed · RHSA-2026:20611
Red Hat Enterprise Linux 8
gnutls-0:3.6.16-8.el8_10.6
Fixed · RHSA-2026:20611
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
gnutls-0:3.6.14-10.el8_4.1
Fixed · RHSA-2026:33125
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
libtasn1-0:4.13-3.el8_4.1
Fixed · RHSA-2026:33125
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
gnutls-0:3.6.14-10.el8_4.1
Fixed · RHSA-2026:33125
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
libtasn1-0:4.13-3.el8_4.1
Fixed · RHSA-2026:33125
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
gnutls-0:3.6.16-5.el8_6.5
Fixed · RHSA-2026:30849
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
libtasn1-0:4.13-3.el8_6.2
Fixed · RHSA-2026:30849
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
gnutls-0:3.6.16-5.el8_6.5
Fixed · RHSA-2026:30849
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
libtasn1-0:4.13-3.el8_6.2
Fixed · RHSA-2026:30849
Red Hat Enterprise Linux 8.8 Telecommunications Update Service
gnutls-0:3.6.16-7.el8_8.4
Fixed · RHSA-2026:30850
Red Hat Enterprise Linux 8.8 Telecommunications Update Service
libtasn1-0:4.13-4.el8_8.1
Fixed · RHSA-2026:30850
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
gnutls-0:3.6.16-7.el8_8.4
Fixed · RHSA-2026:30850
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
libtasn1-0:4.13-4.el8_8.1
Fixed · RHSA-2026:30850
Red Hat Enterprise Linux 9
gnutls-0:3.8.10-4.el9_8
Fixed · RHSA-2026:20612
Red Hat Enterprise Linux 9
gnutls-0:3.8.10-4.el9_8
Fixed · RHSA-2026:20612
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
gnutls-0:3.7.6-21.el9_2.7
Fixed · RHSA-2026:41921
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
gnutls-0:3.8.3-4.el9_4.6
Fixed · RHSA-2026:32962
Red Hat Enterprise Linux 9.6 Extended Update Support
gnutls-0:3.8.3-6.el9_6.4
Fixed · RHSA-2026:30004
Red Hat Hardened Images
gnutls-main-3.8.13-1.hum1
Fixed · RHSA-2026:13274
Red Hat Update Infrastructure 5
rhui5/cds-kubernetes-tp-rhel9:1787241211
Fixed · RHSA-2026:58981
Red Hat Update Infrastructure 5
rhui5/cds-rhel9:1781525684
Fixed · RHSA-2026:26319
Red Hat Update Infrastructure 5
rhui5/haproxy-rhel9:1781525671
Fixed · RHSA-2026:26319
Red Hat Update Infrastructure 5
rhui5/installer-rhel9:1781525693
Fixed · RHSA-2026:26319
Red Hat Update Infrastructure 5
rhui5/installer-tp-rhel9:1787135742
Fixed · RHSA-2026:58981
Red Hat Update Infrastructure 5
rhui5/rhua-rhel9:1781525739
Fixed · RHSA-2026:26319
Red Hat Update Infrastructure 5
rhui5/rhua-tp-rhel9:1787241260
Fixed · RHSA-2026:58981
Red Hat Enterprise Linux 6
gnutls
Affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-8
Fix deferred
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-9
Affected
Red Hat OpenShift Container Platform 4
openshift4/ose-hypershift-rhel9
Under investigation
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Discovery 2 | discovery/discovery-server-rhel9:1782159791 | Fixed | RHSA-2026:29197 |
| Red Hat Discovery 2 | discovery/discovery-ui-rhel9:1782166952 | Fixed | RHSA-2026:29197 |
| Red Hat Enterprise Linux 10 | gnutls-0:3.8.10-4.el10_2 | Fixed | RHSA-2026:20613 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | gnutls-0:3.8.9-9.el10_0.19 | Fixed | RHSA-2026:26409 |
| Red Hat Enterprise Linux 7 Extended Lifecycle Support | gnutls-0:3.3.29-9.el7_9.2 | Fixed | RHSA-2026:43575 |
| Red Hat Enterprise Linux 8 | gnutls-0:3.6.16-8.el8_10.6 | Fixed | RHSA-2026:20611 |
| Red Hat Enterprise Linux 8 | gnutls-0:3.6.16-8.el8_10.6 | Fixed | RHSA-2026:20611 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | gnutls-0:3.6.14-10.el8_4.1 | Fixed | RHSA-2026:33125 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | libtasn1-0:4.13-3.el8_4.1 | Fixed | RHSA-2026:33125 |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | gnutls-0:3.6.14-10.el8_4.1 | Fixed | RHSA-2026:33125 |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | libtasn1-0:4.13-3.el8_4.1 | Fixed | RHSA-2026:33125 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | gnutls-0:3.6.16-5.el8_6.5 | Fixed | RHSA-2026:30849 |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | libtasn1-0:4.13-3.el8_6.2 | Fixed | RHSA-2026:30849 |
| Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | gnutls-0:3.6.16-5.el8_6.5 | Fixed | RHSA-2026:30849 |
| Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | libtasn1-0:4.13-3.el8_6.2 | Fixed | RHSA-2026:30849 |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | gnutls-0:3.6.16-7.el8_8.4 | Fixed | RHSA-2026:30850 |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | libtasn1-0:4.13-4.el8_8.1 | Fixed | RHSA-2026:30850 |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | gnutls-0:3.6.16-7.el8_8.4 | Fixed | RHSA-2026:30850 |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | libtasn1-0:4.13-4.el8_8.1 | Fixed | RHSA-2026:30850 |
| Red Hat Enterprise Linux 9 | gnutls-0:3.8.10-4.el9_8 | Fixed | RHSA-2026:20612 |
| Red Hat Enterprise Linux 9 | gnutls-0:3.8.10-4.el9_8 | Fixed | RHSA-2026:20612 |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | gnutls-0:3.7.6-21.el9_2.7 | Fixed | RHSA-2026:41921 |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | gnutls-0:3.8.3-4.el9_4.6 | Fixed | RHSA-2026:32962 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | gnutls-0:3.8.3-6.el9_6.4 | Fixed | RHSA-2026:30004 |
| Red Hat Hardened Images | gnutls-main-3.8.13-1.hum1 | Fixed | RHSA-2026:13274 |
| Red Hat Update Infrastructure 5 | rhui5/cds-kubernetes-tp-rhel9:1787241211 | Fixed | RHSA-2026:58981 |
| Red Hat Update Infrastructure 5 | rhui5/cds-rhel9:1781525684 | Fixed | RHSA-2026:26319 |
| Red Hat Update Infrastructure 5 | rhui5/haproxy-rhel9:1781525671 | Fixed | RHSA-2026:26319 |
| Red Hat Update Infrastructure 5 | rhui5/installer-rhel9:1781525693 | Fixed | RHSA-2026:26319 |
| Red Hat Update Infrastructure 5 | rhui5/installer-tp-rhel9:1787135742 | Fixed | RHSA-2026:58981 |
| Red Hat Update Infrastructure 5 | rhui5/rhua-rhel9:1781525739 | Fixed | RHSA-2026:26319 |
| Red Hat Update Infrastructure 5 | rhui5/rhua-tp-rhel9:1787241260 | Fixed | RHSA-2026:58981 |
| Red Hat Enterprise Linux 6 | gnutls | Affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Fix deferred | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift4/ose-hypershift-rhel9 | Under investigation | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed May 27, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
May–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.49% (0.00487) | 39.66th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.29% (0.00295) | 20.94th | v5 (v2026.06.15) |
| May 27, 2026 | 0.03% (0.00031) | 9.19th | v4 (v2025.03.14) |
References (22)
- https://access.redhat.com/errata/RHSA-2026:13274 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:20611 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:20612 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:20613 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:26319 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:26409 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:29197 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:30004 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:30849 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:30850 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:32962 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:33125 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:41921 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:43575 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:58981 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:72502 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:74674 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-42012 vdb-entryx_refsource_REDHATVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2467441 issue-trackingx_refsource_REDHATIssue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2026-42012
- https://www.cve.org/CVERecord?id=CVE-2026-42012
- https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-7
Change history (0)
No recorded changes yet.