{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-76166", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-08-19T09:18:28.627Z", "datePublished": "2026-08-19T10:01:28.199Z", "dateUpdated": "2026-11-03T17:46:20.673Z" }, "containers": { "cna": { "title": "Modcluster-core: mod_cluster advertise listener: unauthenticated dos via crafted multicast datagram", "metrics": [ { "other": { "content": { "value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/" }, "type": "Red Hat severity rating" } }, { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "LOW", "baseScore": 4.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1" }, "format": "CVSS" } ], "descriptions": [ { "lang": "en", "value": "A flaw was found in mod_cluster's AdvertiseListenerImpl (org.jboss.modcluster core module). A single crafted UDP multicast datagram with a valid HTTP status line and a \"Server:\" header but without the \"Date:\", \"Digest:\", and \"Sequence:\" headers triggers a NullPointerException in verifyDigest() that is not caught by the worker thread's exception handler. This causes the advertise listener thread to terminate permanently. The failure is silent (isListening() continues to return true) and persists until the node is restarted. The crash occurs before the AdvertiseSecurityKey comparison, so deployments with a configured security key are still affected." } ], "affected": [ { "vendor": "Red Hat", "product": "Red Hat JBoss Web Server 7.0.3", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected", "packageName": "mod_cluster-core", "cpes": [ "cpe:/a:redhat:jboss_enterprise_web_server:7.0" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Web Server 7.0 on RHEL 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "jws7-mod_cluster", "defaultStatus": "affected", "versions": [ { "version": "0:2.1.1-1.Final_redhat_00001.1.el10jws", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el10", "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el8", "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el9" ] }, { "vendor": "Red Hat", "product": "Red 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"cpe:/a:redhat:jboss_enterprise_web_server:7.0::el9" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Web Server 7.0 on RHEL 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "jws7-mod_cluster", "defaultStatus": "affected", "versions": [ { "version": "0:2.1.1-1.Final_redhat_00001.1.el8jws", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el10", "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el8", "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el9" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Web Server 7.0 on RHEL 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "jws7-tomcat", "defaultStatus": "affected", "versions": [ { "version": "0:11.0.21-10.redhat_00010.1.el8jws", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ 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"version": "0:1.3.7-4.redhat_4.el9jws", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el10", "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el8", "cpe:/a:redhat:jboss_enterprise_web_server:7.0::el9" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 7", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "mod_cluster-core", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:jboss_enterprise_application_platform:7" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform 8", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "mod_cluster-core", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:jboss_enterprise_application_platform:8" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "mod_cluster-core", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:jbosseapxp" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Web Server 5", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "mod_cluster-core", "defaultStatus": "unknown", "cpes": [ "cpe:/a:redhat:jboss_enterprise_web_server:5" ] }, { "vendor": "Red Hat", "product": "Red Hat JBoss Web Server 6", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "packageName": "mod_cluster-core", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:jboss_enterprise_web_server:6" ] }, { "vendor": "Red Hat", "product": "Red Hat Single Sign-On 7", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "mod_cluster-core", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:red_hat_single_sign_on:7" ] } ], "references": [ { "url": "https://access.redhat.com/errata/RHSA-2026:93618", "name": "RHSA-2026:93618", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/errata/RHSA-2026:93622", "name": "RHSA-2026:93622", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/security/cve/CVE-2026-76166", "tags": [ "vdb-entry", "x_refsource_REDHAT" ] }, { "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2510883", "name": "RHBZ#2510883", "tags": [ "issue-tracking", "x_refsource_REDHAT" ] } ], "datePublic": "2026-08-04T00:00:00.000Z", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-476", "description": "NULL Pointer Dereference", "lang": "en", "type": "CWE" } ] } ], "x_redhatCweChain": "CWE-476: NULL Pointer Dereference", "workarounds": [ { "lang": "en", "value": "Disable multicast-based proxy advertisement and use static proxy configuration instead. When advertisement must be enabled, ensure the multicast network segment (default 224.0.1.105:23364) is properly isolated and not accessible from untrusted network segments." } ], "timeline": [ { "lang": "en", "time": "2026-07-23T00:00:00.000Z", "value": "Reported to Red Hat." }, { "lang": "en", "time": "2026-08-04T00:00:00.000Z", "value": "Made public." } ], "credits": [ { "lang": "en", "value": "Red Hat would like to thank Kien Pham (Ninh Thanh Cyber Security (NTCS)) and Ta Duc Thien (Ninh Thanh Cyber Security (NTCS)) for reporting this issue." } ], "providerMetadata": { "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-11-03T17:46:20.673Z" }, "x_generator": { "engine": "cvelib 1.8.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-08-20T14:19:26.119248Z", "id": "CVE-2026-76166", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-20T15:23:41.023Z" } } ] } }