CVE-2026-33190 (GCVE-0-2026-33190)

Vulnerability from cvelistv5 – Published: 2026-05-05 19:02 – Updated: 2026-05-06 12:47
VLAI
Title
CoreDNS TSIG authentication bypass on encrypted DNS transports
Summary
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer's TsigStatus() instead of performing verification itself. The DoH and DoH3 writer's TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-303 - Incorrect Implementation of Authentication Algorithm
Assigner
References
Impacted products
Vendor Product Version
coredns coredns Affected: < 1.14.3
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-33190",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-06T12:46:45.291268Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-06T12:47:07.338Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "coredns",
          "vendor": "coredns",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.14.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer\u0027s TsigStatus() instead of performing verification itself. The DoH and DoH3 writer\u0027s TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-303",
              "description": "CWE-303: Incorrect Implementation of Authentication Algorithm",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-05T19:02:55.374Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh"
        },
        {
          "name": "https://github.com/coredns/coredns/releases/tag/v1.14.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/coredns/coredns/releases/tag/v1.14.3"
        }
      ],
      "source": {
        "advisory": "GHSA-qhmp-q7xh-99rh",
        "discovery": "UNKNOWN"
      },
      "title": "CoreDNS TSIG authentication bypass on encrypted DNS transports"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-33190",
    "datePublished": "2026-05-05T19:02:55.374Z",
    "dateReserved": "2026-03-17T22:16:36.721Z",
    "dateUpdated": "2026-05-06T12:47:07.338Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-33190",
      "date": "2026-07-26",
      "epss": "0.00374",
      "percentile": "0.30052"
    },
    "microsoft_vex": {
      "current_release_date": "2026-05-15T14:39:52.000Z",
      "cve": "CVE-2026-33190",
      "id": "msrc_CVE-2026-33190",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "CoreDNS TSIG authentication bypass on encrypted DNS transports",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-33190.json",
      "version": "2"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-33190\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-05-05T20:16:36.167\",\"lastModified\":\"2026-07-24T23:10:00.563\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer\u0027s TsigStatus() instead of performing verification itself. The DoH and DoH3 writer\u0027s TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.\"},{\"lang\":\"es\",\"value\":\"CoreDNS es un servidor DNS que encadena plugins. En versiones anteriores a la 1.14.3, el plugin tsig puede ser eludido en transportes que no son DNS plano (DoT, DoH, DoH3, DoQ y gRPC) porque conf\u00eda en el TsigStatus() del escritor del transporte en lugar de realizar la verificaci\u00f3n por s\u00ed mismo. El TsigStatus() del escritor de DoH y DoH3 siempre devuelve nil, el servidor DoT no establece TsigSecret en el dns.Server, y los escritores de DoQ y gRPC tambi\u00e9n devuelven nil incondicionalmente. Esto permite a un cliente remoto no autenticado eludir la autenticaci\u00f3n basada en TSIG y acceder a recursos destinados a ser restringidos detr\u00e1s de una pol\u00edtica tsig require all. DNS plano sobre TCP y UDP no se ven afectados. Este problema ha sido solucionado en la versi\u00f3n 1.14.3.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"coredns\",\"product\":\"coredns\",\"versions\":[{\"version\":\"\u003c 1.14.3\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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:X/R:X/V:X/RE:X/U:X\",\"baseScore\":8.7,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"HIGH\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-05-06T12:46:45.291268Z\",\"id\":\"CVE-2026-33190\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-303\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:coredns.io:coredns:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.14.3\",\"matchCriteriaId\":\"0B1F8FE2-314C-4C38-9F18-099ACCFF0AAD\"}]}]}],\"references\":[{\"url\":\"https://github.com/coredns/coredns/releases/tag/v1.14.3\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Exploit\",\"Vendor Advisory\"]},{\"url\":\"https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"tags\":[\"Exploit\",\"Vendor Advisory\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-06-28T10:59:58+00:00",
      "cve": "CVE-2026-33190",
      "id": "CVE-2026-33190",
      "initial_release_date": "2026-05-05T19:02:55.374000+00:00",
      "product_status:known_affected": "4",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "github.com/coredns/coredns: CoreDNS: Authentication bypass via flawed TSIG plugin verification on non-plain-DNS transports",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33190.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-06-09T02:23:05Z",
      "cve": "CVE-2026-33190",
      "id": "CVE-2026-33190",
      "initial_release_date": "2026-05-07T02:20:58Z",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-33190",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-33190.json",
      "version": "4"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-33190\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-06T12:46:45.291268Z\"}}}], \"references\": [{\"url\": \"https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-06T12:47:04.599Z\"}}], \"cna\": {\"title\": \"CoreDNS TSIG authentication bypass on encrypted DNS transports\", \"source\": {\"advisory\": \"GHSA-qhmp-q7xh-99rh\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 8.7, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"coredns\", \"product\": \"coredns\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.14.3\"}]}], \"references\": [{\"url\": \"https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh\", \"name\": \"https://github.com/coredns/coredns/security/advisories/GHSA-qhmp-q7xh-99rh\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/coredns/coredns/releases/tag/v1.14.3\", \"name\": \"https://github.com/coredns/coredns/releases/tag/v1.14.3\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer\u0027s TsigStatus() instead of performing verification itself. The DoH and DoH3 writer\u0027s TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-303\", \"description\": \"CWE-303: Incorrect Implementation of Authentication Algorithm\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-05-05T19:02:55.374Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-33190\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-06T12:47:07.338Z\", \"dateReserved\": \"2026-03-17T22:16:36.721Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-05-05T19:02:55.374Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.