CVE-2026-18691

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18691", "assignerOrgId": "a39b4221-9bd0-4244-95fc-f3e2e07f1deb", "state": "PUBLISHED", "assignerShortName": "mongodb", "dateReserved": "2026-08-03T15:53:04.081Z", "datePublished": "2026-08-11T18:46:02.766Z", "dateUpdated": "2026-08-11T20:22:00.933Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "a39b4221-9bd0-4244-95fc-f3e2e07f1deb", "shortName": "mongodb", "dateUpdated": "2026-08-11T18:46:02.766Z"}, "title": "Improper Authentication in MongoDB Intra-Cluster Connections Allows Credential Exposure", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-757", "description": "CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')", "type": "CWE"}]}], "affected": [{"vendor": "MongoDB", "product": "MongoDB Server", "versions": [{"status": "affected", "version": "8.3.0", "lessThan": "8.3.8", "versionType": "semver"}, {"status": "affected", "version": "8.0", "lessThan": "8.0.29", "versionType": "semver"}, {"status": "affected", "version": "7.0", "lessThan": "7.0.40", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment."}]}], "references": [{"url": "https://jira.mongodb.org/browse/SERVER-130264"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "ADJACENT", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "HIGH", "exploitMaturity": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "version": "4.0", "baseSeverity": "CRITICAL", "baseScore": 9, "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 8.8, "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "exploitCodeMaturity": "NOT_DEFINED", "remediationLevel": "NOT_DEFINED", "reportConfidence": "NOT_DEFINED"}}], "source": {"discovery": "INTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.2"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-11T20:21:49.480663Z", "id": "CVE-2026-18691", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-11T20:22:00.933Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-18691", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-08-11T20:21:49.480663Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-11T20:21:56.137Z"}}], "cna": {"title": "Improper Authentication in MongoDB Intra-Cluster Connections Allows Credential Exposure", "source": {"discovery": "INTERNAL"}, "metrics": [{"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9, "Automatable": "NOT_DEFINED", "attackVector": "ADJACENT", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "subAvailabilityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "remediationLevel": "NOT_DEFINED", "reportConfidence": "NOT_DEFINED", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "exploitCodeMaturity": "NOT_DEFINED", "confidentialityImpact": "HIGH"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "MongoDB", "product": "MongoDB Server", "versions": [{"status": "affected", "version": "8.3.0", "lessThan": "8.3.8", "versionType": "semver"}, {"status": "affected", "version": "8.0", "lessThan": "8.0.29", "versionType": "semver"}, {"status": "affected", "version": "7.0", "lessThan": "7.0.40", "versionType": "semver"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://jira.mongodb.org/browse/SERVER-130264"}], "x_generator": {"engine": "Vulnogram 1.0.2"}, "descriptions": [{"lang": "en", "value": "An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment.", "supportingMedia": [{"type": "text/html", "value": "An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-757", "description": "CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')"}]}], "providerMetadata": {"orgId": "a39b4221-9bd0-4244-95fc-f3e2e07f1deb", "shortName": "mongodb", "dateUpdated": "2026-08-11T18:46:02.766Z"}}}, "cveMetadata": {"cveId": "CVE-2026-18691", "state": "PUBLISHED", "dateUpdated": "2026-08-11T20:22:00.933Z", "dateReserved": "2026-08-03T15:53:04.081Z", "assignerOrgId": "a39b4221-9bd0-4244-95fc-f3e2e07f1deb", "datePublished": "2026-08-11T18:46:02.766Z", "assignerShortName": "mongodb"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "MongoDB Server", "vendor": "MongoDB", "versions": [{"lessThan": "8.3.8", "status": "affected", "version": "8.3.0", "versionType": "semver"}, {"lessThan": "8.0.29", "status": "affected", "version": "8.0", "versionType": "semver"}, {"lessThan": "7.0.40", "status": "affected", "version": "7.0", "versionType": "semver"}]}], "source": "cna@mongodb.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "matchCriteriaId": "F3DB18E4-812C-4E04-802D-5D6B61CE9D1B", "versionEndExcluding": "7.0.40", "versionStartIncluding": "7.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "matchCriteriaId": "4DC64BC6-1D47-4809-9616-95A7CF59DC37", "versionEndExcluding": "8.0.29", "versionStartIncluding": "8.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "matchCriteriaId": "7BCD6B05-9FD5-4283-A2AC-8B625425597F", "versionEndIncluding": "8.2.12", "versionStartIncluding": "8.2.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "matchCriteriaId": "6EE4503A-F53C-432E-9DDB-F488DD989E8A", "versionEndExcluding": "8.3.8", "versionStartIncluding": "8.3.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mongodb:mongodb:9.0.0:alpha0:*:*:-:-:*:*", "matchCriteriaId": "0FB52026-6C88-4401-84B5-3A070F0906D4", "vulnerable": true}, {"criteria": "cpe:2.3:a:mongodb:mongodb:9.0.0:alpha1:*:*:-:-:*:*", "matchCriteriaId": "8D32A105-731C-493E-8CBF-639204CDAC7C", "vulnerable": true}, {"criteria": "cpe:2.3:a:mongodb:mongodb:9.1.0:alpha0:*:*:-:-:*:*", "matchCriteriaId": "D56E512D-83F8-4D51-8690-E92F6A006822", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue in MongoDB Server's intra-cluster connection setup could allow a party with suitable network access to influence which authentication mechanism is used when one replica set member connects to another. Under certain conditions, this could cause the cluster's shared internal credential to be transmitted in a less-protected form, potentially allowing that credential to be recovered. If recovered, the credential could be used to authenticate as the internal superuser to nodes in the deployment."}, {"lang": "es", "value": "Un problema en la configuraci\u00f3n de conexi\u00f3n intra-cl\u00faster del servidor MongoDB podr\u00eda permitir a una parte con acceso de red adecuado influir en qu\u00e9 mecanismo de autenticaci\u00f3n se utiliza cuyo un miembro del conjunto de r\u00e9plicas se conecta a otro. Bajo ciertas condiciones, esto podr\u00eda causar que la credencial interna compartida del cl\u00faster se transmita en una forma menos protegida, permitiendo potencialmente que esa credencial sea recuperada. Si se recupera, la credencial podr\u00eda usarse para autenticarse como el superusuario interno en los nodos de la implementaci\u00f3n."}], "id": "CVE-2026-18691", "lastModified": "2026-10-23T21:10:00.157", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "cna@mongodb.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "ADJACENT", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.0, "baseSeverity": "CRITICAL", "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": "HIGH", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "cna@mongodb.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-18691", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-11T20:21:49.480663Z", "version": "2.0.3"}}]}, "published": "2026-08-11T19:17:22.903", "references": [{"source": "cna@mongodb.com", "tags": ["Vendor Advisory", "Issue Tracking"], "url": "https://jira.mongodb.org/browse/SERVER-130264"}], "sourceIdentifier": "cna@mongodb.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-757"}], "source": "cna@mongodb.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[8.3.0,8.3.8)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[8.0,8.0.29)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[7.0,7.0.40)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "MongoDB Server", "source": "cna", "vendor": "MongoDB"}, "product": "mongodb_server", "vendor": "mongodb"}], "created": "2026-08-12T12:30:03.847390+00:00", "updated": "2026-08-12T19:45:08.179432+00:00", "vendors": ["mongodb", "mongodb$PRODUCT$mongodb_server"]}