{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-127030", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-11-12T10:45:33.541Z", "datePublished": "2026-11-12T16:21:52.568Z", "dateUpdated": "2026-11-12T16:21:52.568Z"}, "containers": {"cna": {"title": "Freeradius: stack buffer overflow via unchecked eap-fast sessionticket length", "metrics": [{"other": {"content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "format": "CVSS"}], "descriptions": [{"lang": "en", "value": "A flaw was found in freeradius. An improper length validation in the EAP-FAST module allows a stack-based buffer overflow during session ticket processing. A remote, unauthenticated attacker can exploit this flaw by sending a specially crafted handshake request, causing the server process to crash and resulting in a Denial of Service (DoS)."}], "affected": [{"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "freeradius", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:10"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "freeradius", "defaultStatus": "unaffected", "cpes": ["cpe:/o:redhat:rhel_els:6"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "freeradius", "defaultStatus": "affected", "cpes": ["cpe:/o:redhat:rhel_els:7"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "freeradius:3.0/freeradius", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:8"]}, {"vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "freeradius", "defaultStatus": "affected", "cpes": ["cpe:/a:redhat:enterprise_linux:9"]}], "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-127030", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2572340", "name": "RHBZ#2572340", "tags": ["issue-tracking", "x_refsource_REDHAT"]}, {"url": "https://github.com/FreeRADIUS/freeradius-server/commit/064567a08f3b9d9b4863fab6060fafe296ac7de9"}, {"url": "https://github.com/FreeRADIUS/freeradius-server/commit/a5d09dad528d7a3a3c4c01158716ab85a12e09ef"}], "datePublic": "2026-11-12T12:12:02.163Z", "problemTypes": [{"descriptions": [{"cweId": "CWE-787", "description": "Out-of-bounds Write", "lang": "en", "type": "CWE"}]}], "x_redhatCweChain": "CWE-787: Out-of-bounds Write", "workarounds": [{"lang": "en", "value": "Disable the EAP-FAST submodule in the FreeRADIUS configuration, or restrict incoming RADIUS traffic to trusted network access points.\n\n1. Disable EAP-FAST:\nIn `/etc/raddb/mods-available/eap` (or `/etc/raddb/eap.conf`), comment out the `fast` section within the `eap` configuration block and verify that `default_eap_type` is not set to `fast`.\n\n2. Apply configuration changes:\n```\nsystemctl restart radiusd\n```\n\n3. Limit network exposure:\nRestrict UDP port 1812 to authorized Network Access Server (NAS) clients using firewalld:\n```\nfirewall-cmd --permanent --zone=internal --add-source=<TRUSTED_IP_OR_SUBNET>\nfirewall-cmd --permanent --zone=internal --add-port=1812/udp\nfirewall-cmd --reload\n```\n\nCaveats:\nDisabling EAP-FAST prevents authentication for any network clients that rely exclusively on EAP-FAST. Restricting firewall rules will block traffic from unlisted authenticator sources.\n\nWarning:\nRestarting or reloading the radiusd service will temporarily disrupt active RADIUS authentication processing."}], "timeline": [{"lang": "en", "time": "2026-11-03T10:16:22.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-11-12T12:12:02.163Z", "value": "Made public."}], "credits": [{"lang": "en", "value": "Red Hat would like to thank s4cr00t (Alipay Security Team) for reporting this issue. Upstream acknowledges Ada Logics and TristanInSec@gmail.com as the original reporters."}], "providerMetadata": {"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-11-12T16:21:52.568Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

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{"affected": [{"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:10"], "defaultStatus": "affected", "packageName": "freeradius", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:rhel_els:6"], "defaultStatus": "unaffected", "packageName": "freeradius", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:rhel_els:7"], "defaultStatus": "affected", "packageName": "freeradius", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "freeradius:3.0/freeradius", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "freeradius", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}], "source": "secalert@redhat.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in freeradius. An improper length validation in the EAP-FAST module allows a stack-based buffer overflow during session ticket processing. A remote, unauthenticated attacker can exploit this flaw by sending a specially crafted handshake request, causing the server process to crash and resulting in a Denial of Service (DoS)."}], "id": "CVE-2026-127030", "lastModified": "2026-11-12T17:17:43.283", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "secalert@redhat.com", "type": "Primary"}]}, "published": "2026-11-12T17:17:43.150", "references": [{"source": "secalert@redhat.com", "url": "https://access.redhat.com/security/cve/CVE-2026-127030"}, {"source": "secalert@redhat.com", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2572340"}, {"source": "secalert@redhat.com", "url": "https://github.com/FreeRADIUS/freeradius-server/commit/064567a08f3b9d9b4863fab6060fafe296ac7de9"}, {"source": "secalert@redhat.com", "url": "https://github.com/FreeRADIUS/freeradius-server/commit/a5d09dad528d7a3a3c4c01158716ab85a12e09ef"}], "sourceIdentifier": "secalert@redhat.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "secalert@redhat.com", "type": "Primary"}]}

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