CVE-2026-33594
Full vulnerability record from the local CVENow database.
Description
A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.
Severity
HIGH
CVSS score
7.5
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-04-22 14:16:53.837000
Last modified
2026-10-26 21:10:00.170000
View original CVE JSON
{
"id": "CVE-2026-33594",
"sourceIdentifier": "[email protected]",
"published": "2026-04-22T14:16:53.837",
"lastModified": "2026-10-26T21:10:00.170",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection."
},
{
"lang": "es",
"value": "Un cliente puede desencadenar una asignación excesiva de memoria al generar muchas consultas que se enrutan a un backend DoH sobrecargado, lo que provoca que las consultas se acumulen en un búfer que no se liberará hasta el final de la conexión."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "PowerDNS",
"product": "DNSdist",
"defaultStatus": "unaffected",
"collectionURL": "https://repo.powerdns.com/",
"packageName": "dnsdist",
"modules": [
"Outgoing DNS over HTTPS"
],
"programFiles": [
"dnsdist-nghttp2.cc"
],
"repo": "https://github.com/PowerDNS/pdns",
"versions": [
{
"version": "1.9.0",
"lessThan": "1.9.13",
"versionType": "semver",
"status": "affected"
},
{
"version": "2.0.0",
"lessThan": "2.0.4",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "LOW"
},
"exploitabilityScore": 3.9,
"impactScore": 1.4
},
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-04-22T14:36:44.423277Z",
"id": "CVE-2026-33594",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-770"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:powerdns:dnsdist:*:*:*:*:*:*:*:*",
"versionStartIncluding": "1.9.0",
"versionEndExcluding": "1.9.13",
"matchCriteriaId": "DCC2DF11-EC5C-4112-90F2-C266CB65D390"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:a:powerdns:dnsdist:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.0.0",
"versionEndExcluding": "2.0.4",
"matchCriteriaId": "29865EC6-C1A0-40F3-B0BB-7F71F9C1DCB7"
}
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}
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}
],
"references": [
{
"url": "https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
}
]
}