{"api_version":"1","generated_at":"2026-05-04T12:31:18+00:00","cve":"CVE-2026-3833","urls":{"html":"https://cve.report/CVE-2026-3833","api":"https://cve.report/api/cve/CVE-2026-3833.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-3833","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-3833"},"summary":{"title":"Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison","description":"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.","state":"PUBLISHED","assigner":"redhat","published_at":"2026-04-30 18:16:30","updated_at":"2026-05-03 20:16:02"},"problem_types":["CWE-178","CWE-178 Improper Handling of Case Sensitivity"],"metrics":[{"version":"3.1","source":"secalert@redhat.com","type":"Secondary","score":"6.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"6.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"references":[{"url":"https://gitlab.com/gnutls/gnutls/-/issues/1803","name":"https://gitlab.com/gnutls/gnutls/-/issues/1803","refsource":"134c704f-9b21-4f2e-91b3-4a467353bcc0","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://access.redhat.com/errata/RHSA-2026:13274","name":"https://access.redhat.com/errata/RHSA-2026:13274","refsource":"secalert@redhat.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://access.redhat.com/security/cve/CVE-2026-3833","name":"https://access.redhat.com/security/cve/CVE-2026-3833","refsource":"secalert@redhat.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2445763","name":"https://bugzilla.redhat.com/show_bug.cgi?id=2445763","refsource":"secalert@redhat.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-3833","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3833","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"unaffected 3.8.13-1.hum1 * rpm","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","version":"","platforms":[]}],"timeline":[{"source":"CNA","time":"2026-03-09T14:02:09.783Z","lang":"en","value":"Reported to Red Hat."},{"source":"CNA","time":"2026-04-30T17:26:28.969Z","lang":"en","value":"Made public."}],"solutions":[],"workarounds":[{"source":"CNA","title":"","value":"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.","time":"","lang":"en"}],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"3833","cve":"CVE-2026-3833","epss":"0.000300000","percentile":"0.085880000","score_date":"2026-05-03","updated_at":"2026-05-04 00:13:04"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-3833","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-04-30T18:37:27.251775Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-04-30T18:37:57.245Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"references":[{"tags":["exploit"],"url":"https://gitlab.com/gnutls/gnutls/-/issues/1803"}],"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"affected","packageName":"gnutls-main","product":"Red Hat Hardened Images","vendor":"Red Hat","versions":[{"lessThan":"*","status":"unaffected","version":"3.8.13-1.hum1","versionType":"rpm"}]},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"],"defaultStatus":"affected","packageName":"gnutls","product":"Red Hat Enterprise Linux 10","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"],"defaultStatus":"affected","packageName":"gnutls","product":"Red Hat Enterprise Linux 6","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"],"defaultStatus":"affected","packageName":"gnutls","product":"Red Hat Enterprise Linux 7","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"],"defaultStatus":"affected","packageName":"gnutls","product":"Red Hat Enterprise Linux 8","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"],"defaultStatus":"affected","packageName":"gnutls","product":"Red Hat Enterprise Linux 9","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:openshift:4"],"defaultStatus":"affected","packageName":"rhcos","product":"Red Hat OpenShift Container Platform 4","vendor":"Red Hat"}],"datePublic":"2026-04-30T17:26:28.969Z","descriptions":[{"lang":"en","value":"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."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Moderate"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-178","description":"Improper Handling of Case Sensitivity","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-03T19:27:37.996Z","orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","shortName":"redhat"},"references":[{"name":"RHSA-2026:13274","tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:13274"},{"tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-3833"},{"name":"RHBZ#2445763","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2445763"},{"url":"https://gitlab.com/gnutls/gnutls/-/issues/1803"}],"timeline":[{"lang":"en","time":"2026-03-09T14:02:09.783Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-04-30T17:26:28.969Z","value":"Made public."}],"title":"Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison","workarounds":[{"lang":"en","value":"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."}],"x_generator":{"engine":"cvelib 1.8.0"},"x_redhatCweChain":"CWE-178: Improper Handling of Case Sensitivity"}},"cveMetadata":{"assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","assignerShortName":"redhat","cveId":"CVE-2026-3833","datePublished":"2026-04-30T17:37:05.818Z","dateReserved":"2026-03-09T14:00:51.698Z","dateUpdated":"2026-05-03T19:27:37.996Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-30 18:16:30","lastModifiedDate":"2026-05-03 20:16:02","problem_types":["CWE-178","CWE-178 Improper Handling of Case Sensitivity"],"metrics":{"cvssMetricV31":[{"source":"secalert@redhat.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":2.5}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"3833","Ordinal":"1","Title":"Gnutls: gnutls: policy bypass due to case-sensitive nameconstrai","CVE":"CVE-2026-3833","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"3833","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Gnutls: gnutls: policy bypass due to case-sensitive nameconstrai"}]}}}