{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90668", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "state": "PUBLISHED", "assignerShortName": "mitre", "dateReserved": "2026-09-13T02:00:53.718Z", "datePublished": "2026-09-13T02:00:54.190Z", "dateUpdated": "2026-09-13T02:00:54.190Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "modules": ["webserver"], "product": "UnrealIRCd", "programFiles": ["src/modules/webserver.c"], "programRoutines": [{"name": "webserver_handle_request_header()"}], "repo": "https://github.com/unrealircd/unrealircd", "vendor": "UnrealIRCd", "versions": [{"lessThan": "6.2.7", "status": "affected", "version": "6.0.5", "versionType": "semver"}]}], "configurations": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "A websocket or rpc listener is enabled (listen::options::websocket or listen::options::rpc)."}], "value": "A websocket or rpc listener is enabled (listen::options::websocket or listen::options::rpc)."}], "descriptions": [{"lang": "en", "value": "The webserver in UnrealIRCd 6.0.5 through 6.2.6 before 6.2.7 does not limit the number of HTTP request headers, which allows remote attackers to cause a denial of service (memory consumption and unresponsive server) via an HTTP request with an unlimited number of headers, if a websocket or JSON-RPC listener is enabled (disabled by default)."}], "metrics": [{"cvssV4_0": {"Automatable": "YES", "Recovery": "AUTOMATIC", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 8.7, "baseSeverity": "HIGH", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A/RE:L", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "LOW"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"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", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-770", "description": "CWE-770 Allocation of Resources Without Limits or Throttling", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-09-13T02:00:54.190Z"}, "references": [{"url": "https://www.unrealircd.org/"}, {"url": "https://forums.unrealircd.org/viewtopic.php?t=9483"}], "solutions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Upgrade to UnrealIRCd 6.2.7 or later. Alternatively, apply the hot-patch to fix the issue without restart: ./unrealircd hot-patch webserver-header-dos<br><br>"}], "value": "Upgrade to UnrealIRCd 6.2.7 or later. Alternatively, apply the hot-patch to fix the issue without restart: ./unrealircd hot-patch webserver-header-dos"}], "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Remove the websocket and rpc options from your listen blocks until the patch or upgrade is applied.<br><br>"}], "value": "Remove the websocket and rpc options from your listen blocks until the patch or upgrade is applied."}], "x_generator": {"engine": "CVE-Request-form 0.0.1"}, "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:unrealircd:unrealircd:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0.5", "versionEndExcluding": "6.2.7"}]}]}]}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "modules": ["webserver"], "product": "UnrealIRCd", "programFiles": ["src/modules/webserver.c"], "programRoutines": [{"name": "webserver_handle_request_header()"}], "repo": "https://github.com/unrealircd/unrealircd", "vendor": "UnrealIRCd", "versions": [{"lessThan": "6.2.7", "status": "affected", "version": "6.0.5", "versionType": "semver"}]}], "source": "[email protected]"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The webserver in UnrealIRCd 6.0.5 through 6.2.6 before 6.2.7 does not limit the number of HTTP request headers, which allows remote attackers to cause a denial of service (memory consumption and unresponsive server) via an HTTP request with an unlimited number of headers, if a websocket or JSON-RPC listener is enabled (disabled by default)."}], "id": "CVE-2026-90668", "lastModified": "2026-09-13T02:17:05.103", "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": "[email protected]", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "YES", "Recovery": "AUTOMATIC", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:L/U:X", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "LOW"}, "source": "[email protected]", "type": "Secondary"}]}, "published": "2026-09-13T02:17:05.103", "references": [{"source": "[email protected]", "url": "https://forums.unrealircd.org/viewtopic.php?t=9483"}, {"source": "[email protected]", "url": "https://www.unrealircd.org/"}], "sourceIdentifier": "[email protected]", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-770"}], "source": "[email protected]", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.0.5,6.2.7)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "UnrealIRCd", "source": "cna", "vendor": "UnrealIRCd"}, "product": "unrealircd", "vendor": "unrealircd"}], "created": "2026-09-13T08:00:12.109747+00:00", "title": "UnrealIRCd Webserver Header DoS via Unlimited HTTP Headers", "updated": "2026-09-13T12:15:05.816772+00:00", "vendors": ["unrealircd", "unrealircd$PRODUCT$unrealircd"]}