# CVE-2026-5419: Gnutls: gnutls: information disclosure via timing side-channel in pkcs#7 padding removal

Status: published. Published: 2026-06-01. Updated: 2026-11-03.

A flaw was found in gnutls. The PKCS#7 padding check, performed during decryption, was not constant-time. This timing side-channel could allow a remote attacker to potentially leak sensitive information about the padding bytes through observable timing differences. This vulnerability is a form of information disclosure.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. (source: CNA: redhat)

## Affected products and versions

-  /  (gnutls): 0 (affected). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (gnutls): ≥ 0:3.8.10-4.el10_2; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10.0 Extended Update Support (gnutls): ≥ 0:3.8.9-9.el10_0.19; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (gnutls): ≥ 0:3.8.10-4.el9_8; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions (gnutls): ≥ 0:3.8.3-4.el9_4.6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.6 Extended Update Support (gnutls): ≥ 0:3.8.3-6.el9_6.4; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.17 (cert-manager/jetstack-cert-manager-acmesolver-rhel9): ≥ 1791371080; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.17 (cert-manager/jetstack-cert-manager-rhel9): ≥ 1791371069; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.17 (cert-manager/cert-manager-operator-rhel9): ≥ 1791788287; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.17 (cert-manager/cert-manager-operator-bundle): ≥ 1791970484; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.18 (cert-manager/jetstack-cert-manager-acmesolver-rhel9): ≥ 1791459707; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.18 (cert-manager/jetstack-cert-manager-rhel9): ≥ 1791459711; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.18 (cert-manager/cert-manager-istio-csr-rhel9): ≥ 1791459759; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.18 (cert-manager/cert-manager-operator-rhel9): ≥ 1789029076; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.18 (cert-manager/cert-manager-operator-bundle): ≥ 1791966259; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Cert Manager support for Red Hat OpenShift release 1.20 (cert-manager/cert-manager-trust-manager-rhel9): ≥ 1790598593; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Discovery 2 (discovery/discovery-server-rhel9): ≥ 1782159791; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Discovery 2 (discovery/discovery-ui-rhel9): ≥ 1782166952; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (gnutls-main): ≥ 3.8.13-1.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift AI 3.4 (rhai/base-image-neuron-rhel9): ≥ 1790703542; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/cds-rhel9): ≥ 1781525684; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/haproxy-rhel9): ≥ 1781525671; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/installer-rhel9): ≥ 1781525693; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/rhua-rhel9): ≥ 1781525739; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/cds-kubernetes-tp-rhel9): ≥ 1787241211; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/installer-tp-rhel9): ≥ 1787135742; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Update Infrastructure 5 (rhui5/rhua-tp-rhel9): ≥ 1787241260; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (gnutls): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (gnutls): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (gnutls): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift4/ose-hypershift-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N; source: CNA: redhat

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.54% as of 2026-11-03; percentile 45.68%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-208

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:13274 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:20612 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:20613 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:26319 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:26409 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:29197 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:30004 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:32962 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:58981 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:72502 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:74674 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82304 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82322 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82347 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82354 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82372 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82857 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:82888 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-5419 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2467686 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-13 (CNA: redhat)

- https://access.redhat.com/errata/RHSA-2026:13274 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:20612 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:20613 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:26319 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:26409 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:29197 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:30004 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:32962 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:58981 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:72502 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:74674 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82304 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82322 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82347 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82354 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82372 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82857 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:82888 (secalert@redhat.com)

- https://access.redhat.com/security/cve/CVE-2026-5419 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2467686 (secalert@redhat.com)

- https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-13 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-5419; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5419; retrieved 2026-11-04; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-5419; retrieved 2026-11-03; source updated Not reported

Revision: bd483b053fe6751b7f2811d8d9eb89c2bf1bb8a739da761876c6d087ba66a3ed

Canonical: https://y2.dev/cve/CVE-2026-5419

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.