Gnutls: stack-based buffer overflow in gnutls_pkcs11_token_init() function
Priority LOW 18CWE-121Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Partial Red Hat: 13 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
A flaw was found in the GnuTLS library, specifically in the gnutls_pkcs11_token_init() function that handles PKCS#11 token initialization. When a token label longer than expected is processed, the function writes past the end of a fixed-size stack buffer. This programming error can cause the application using GnuTLS to crash or, in certain conditions, be exploited for code execution. As a result, systems or applications relying on GnuTLS may be vulnerable to a denial of service or local privilege escalation attacks.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00222 12th percentileScored 2026-11-07
Fix Partial Red Hat: 13 advisoriesRed Hat: 13 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | gnutls | 3.8.1; 3.8.2; 3.8.3; 3.8.4; 3.8.5; 3.8.6; 3.8.7; 3.8.8; 3.8.9; 3.8.10 | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 10 | — | 3.8.10-3.el10_1 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 3.6.16-8.el8_10.5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 3.6.16-8.el8_10.5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 3.8.3-10.el9_7 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 3.8.3-10.el9_7 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-4.1777325677 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-4.1777325711 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-4.1777325710 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-3.1777325680 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-4.1777325709 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-4.1777325680 | Patch available | CNA |
| Red Hat | RHEL-8 based Middleware Containers | — | 7.13.5-4.1777325708 | Patch available | CNA |
| Red Hat | Cert Manager support for Red Hat OpenShift release 1.18 | — | 1791459707 | Patch available | CNA |
| Red Hat | Cert Manager support for Red Hat OpenShift release 1.18 | — | 1791459711 | Patch available | CNA |
| Red Hat | Cert Manager support for Red Hat OpenShift release 1.18 | — | 1791459759 | Patch available | CNA |
| Red Hat | Cert Manager support for Red Hat OpenShift release 1.18 | — | 1789029076 | Patch available | CNA |
| Red Hat | Cert Manager support for Red Hat OpenShift release 1.18 | — | 1791966259 | Patch available | CNA |
| Red Hat | Red Hat Ceph Storage 8 | — | 1774002867 | Patch available | CNA |
| Red Hat | Red Hat Discovery 2 | — | 1775668717 | Patch available | CNA |
| Red Hat | Red Hat Discovery 2 | — | 1775675922 | Patch available | CNA |
| Red Hat | Red Hat Hardened Images | — | 3.8.12-1.1.hum1 | Patch available | CNA |
| Red Hat | Red Hat Insights proxy 1.5 | — | 1773685509 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1773670073 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1773672059 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1773668803 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1773670137 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
- gnutls Vendor— Affected 3.8.1; 3.8.2; 3.8.3; 3.8.4; 3.8.5; 3.8.6; 3.8.7; 3.8.8; 3.8.9; 3.8.10 Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 3.8.10-3.el10_1 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 3.6.16-8.el8_10.5 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 3.6.16-8.el8_10.5 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 3.8.3-10.el9_7 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 3.8.3-10.el9_7 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-4.1777325677 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-4.1777325711 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-4.1777325710 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-3.1777325680 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-4.1777325709 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-4.1777325680 Patch available CNA
- RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.13.5-4.1777325708 Patch available CNA
- Cert Manager support for Red Hat OpenShift release 1.18 VendorRed Hat Affected — Fixed in 1791459707 Patch available CNA
- Cert Manager support for Red Hat OpenShift release 1.18 VendorRed Hat Affected — Fixed in 1791459711 Patch available CNA
- Cert Manager support for Red Hat OpenShift release 1.18 VendorRed Hat Affected — Fixed in 1791459759 Patch available CNA
- Cert Manager support for Red Hat OpenShift release 1.18 VendorRed Hat Affected — Fixed in 1789029076 Patch available CNA
- Cert Manager support for Red Hat OpenShift release 1.18 VendorRed Hat Affected — Fixed in 1791966259 Patch available CNA
- Red Hat Ceph Storage 8 VendorRed Hat Affected — Fixed in 1774002867 Patch available CNA
- Red Hat Discovery 2 VendorRed Hat Affected — Fixed in 1775668717 Patch available CNA
- Red Hat Discovery 2 VendorRed Hat Affected — Fixed in 1775675922 Patch available CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in 3.8.12-1.1.hum1 Patch available CNA
- Red Hat Insights proxy 1.5 VendorRed Hat Affected — Fixed in 1773685509 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1773670073 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1773672059 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1773668803 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1773670137 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 15
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/o:redhat:enterprise_linux:10.1 | 10.1 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8::appstream | 8 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:8::baseos | 8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9::appstream | 9 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:9::baseos | 9 | — | Red Hat |
| cpe:/a:redhat:rhosemc:1.0::el8 | 1.0 | — | Red Hat |
| cpe:/a:redhat:cert_manager:1.18::el9 | 1.18 | — | Red Hat |
| cpe:/a:redhat:ceph_storage:8::el9 | 8 | — | Red Hat |
| cpe:/a:redhat:discovery:2::el9 | 2 | — | Red Hat |
| cpe:/a:redhat:hummingbird:1 | 1 | — | Red Hat |
- cpe:/o:redhat:enterprise_linux:10.1 Versions 10.1 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8::appstream Versions 8 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:8::baseos Versions 8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9::appstream Versions 9 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:9::baseos Versions 9 — ·Red Hat
- cpe:/a:redhat:rhosemc:1.0::el8 Versions 1.0 — ·Red Hat
- cpe:/a:redhat:cert_manager:1.18::el9 Versions 1.18 — ·Red Hat
- cpe:/a:redhat:ceph_storage:8::el9 Versions 8 — ·Red Hat
- cpe:/a:redhat:discovery:2::el9 Versions 2 — ·Red Hat
- cpe:/a:redhat:hummingbird:1 Versions 1 — ·Red Hat
Remediation
Red Hat 13 advisories
- RHSA-2026:82857 Released 2026-10-14 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-bundle
- RHSA-2026:82372 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:82354 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
Show 10 more Red Hat advisories
- RHSA-2026:82347 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:13812 Released 2026-05-05 · Red Hat rating Importantupdated RHEL-8 based Middleware Containers container images
- Middleware Containers for OpenShift rhpam-7/rhpam-businesscentral-monitoring-rhel8, rhpam-7/rhpam-businesscentral-rhel8, rhpam-7/rhpam-controller-rhel8 +4
- RHSA-2026:7477 Released 2026-04-10 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images gnutls-3.8.12-1.1.hum1@aarch64, gnutls-3.8.12-1.1.hum1@src, gnutls-3.8.12-1.1.hum1@x86_64 +14
- RHSA-2026:7329 Released 2026-04-09 · Red Hat rating ImportantA Subscription Management tool for finding and reporting Red Hat product usage
- Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
- RHSA-2026:5585 Released 2026-03-24 · Red Hat rating Moderategnutls security update
- Red Hat Enterprise Linux AppStream (v. 8) gnutls-c++-3.6.16-8.el8_10.5, gnutls-dane-3.6.16-8.el8_10.5, gnutls-devel-3.6.16-8.el8_10.5 +1
- Red Hat Enterprise Linux BaseOS (v. 8) gnutls-3.6.16-8.el8_10.5
- RHSA-2026:5606 Released 2026-03-24 · Red Hat rating ImportantRed Hat Ceph Storage
- Red Hat Ceph Storage 8 registry.redhat.io/rhceph/rhceph-8-rhel9
- RHSA-2026:4943 Released 2026-03-18 · Red Hat rating ImportantRed Hat Update Infrastructure 5.1 security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9, registry.redhat.io/rhui5/installer-rhel9 +1
- RHSA-2026:4655 Released 2026-03-16 · Red Hat rating ModerateInsights proxy Container Image
- Red Hat Insights proxy 1.5 registry.redhat.io/insights-proxy/insights-proxy-container-rhel9
- RHSA-2026:4188 Released 2026-03-10 · Red Hat rating Moderategnutls security update
- Red Hat Enterprise Linux AppStream (v. 9) gnutls-c++-3.8.3-10.el9_7, gnutls-dane-3.8.3-10.el9_7, gnutls-devel-3.8.3-10.el9_7 +1
- Red Hat Enterprise Linux BaseOS (v. 9) gnutls-3.8.3-10.el9_7
- RHSA-2026:3477 Released 2026-03-02 · Red Hat rating Moderategnutls security update
- Red Hat Enterprise Linux AppStream (v. 10) gnutls-c++-3.8.10-3.el10_1, gnutls-dane-3.8.10-3.el10_1, gnutls-devel-3.8.10-3.el10_1 +2
- Red Hat Enterprise Linux BaseOS (v. 10) gnutls-3.8.10-3.el10_1
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Cert Manager support for Red Hat OpenShift release 1.18 | Fixed | RHSA-2026:82347, RHSA-2026:82354, RHSA-2026:82372, RHSA-2026:82857 |
| Middleware Containers for OpenShift | Fixed | RHSA-2026:13812 |
| Red Hat Ceph Storage 8 | Fixed | RHSA-2026:5606 |
| Red Hat Discovery 2 | Fixed | RHSA-2026:7329 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:3477 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:5585 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:4188 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:3477 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:5585 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:4188 |
| Red Hat Hardened Images | Fixed | RHSA-2026:7477 |
| Red Hat Insights proxy 1.5 | Fixed | RHSA-2026:4655 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:4943 |
Not affected: 1 product
- Middleware Containers for OpenShift
Timeline
- 2026-10-02 Threatist record created from CVE-2025-9820
- 2026-10-03 Alias added: GHSA-337w-h8w7-m899
- 2026-10-14 Fix available: cert-manager/cert-manager-istio-csr-rhel9@1791459759, cert-manager/cert-manager-operator-rhel9@1789029076, cert-manager/jetstack-cert-manager-acmesolver-rhel9@1791459707 +1 · CNA
- 2026-10-14 3 new references · CNA
- 2026-10-14 Fix available: RHSA-2026:82372 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82354 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82347 · Red Hat
- 2026-10-15 Fix available: RHSA-2026:82857 · Red Hat
- 2026-10-15 Fix available: cert-manager/cert-manager-operator-bundle@1791966259 · CNA
- 2026-10-15 1 new reference · CNA
- 2026-10-16 Fix available: Cert Manager support for Red Hat OpenShift release 1.18 · Red Hat
References
Advisory 13
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Sources
- CVE-2025-9820 · CVE Program
- CVE-2025-9820 · NVD
- FIRST EPSS
- GHSA-337w-h8w7-m899 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-9820 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences