CVE-2026-82021

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-82021", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-08-27T21:39:20.459Z", "datePublished": "2026-08-28T18:50:38.180Z", "dateUpdated": "2026-08-31T18:50:59.520Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-08-29T11:48:19.100Z"}, "title": "Hermes Agent 0.18.2 < 0.19.0 MCP Catalog Supply Chain RCE via Mutable Branch Reference", "descriptions": [{"lang": "en", "value": "Hermes Agent 0.18.2 prior to 0.19.0 contains a supply chain vulnerability in its bundled MCP catalog that allows a remote attacker to execute arbitrary code by compromising a third-party upstream repository referenced via a mutable branch rather than a pinned commit SHA. An attacker who compromises the upstream repository can propagate malicious code to every host that installs the affected catalog entry, with no further action required by the operator."}], "tags": ["x_open-source"], "datePublic": "2026-07-14T00:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-494", "description": "Download of Code Without Integrity Check", "type": "CWE"}]}], "affected": [{"defaultStatus": "affected", "vendor": "NousResearch", "product": "hermes-agent", "packageURL": "pkg:github/NousResearch/hermes-agent", "repo": "https://github.com/NousResearch/hermes-agent", "versions": [{"status": "affected", "version": "0.18.2", "versionType": "semver", "lessThan": "0.19.0"}, {"status": "affected", "version": "2026.7.7.2", "versionType": "custom", "lessThan": "2026.7.20"}]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "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:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "version": "3.1", "baseSeverity": "HIGH", "baseScore": 8.3, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H"}}], "references": [{"url": "https://github.com/NousResearch/hermes-agent/releases/tag/v2026.7.20", "name": "Hermes Agent v2026.7.20 Release Notes", "tags": ["release-notes"]}, {"url": "https://github.com/NousResearch/hermes-agent/pull/64463", "name": "Pull Request", "tags": ["issue-tracking", "patch"]}, {"url": "https://github.com/NousResearch/hermes-agent/commit/9df5f879b4a5925c0f8f947e7e16ed8e845932c3", "name": "Patch Commit", "tags": ["patch"]}, {"url": "https://www.vulncheck.com/advisories/hermes-agent-mcp-catalog-supply-chain-rce-via-mutable-branch-reference", "tags": ["third-party-advisory"]}], "credits": [{"lang": "en", "value": "Zubair Ashraf (@zashraf1337), Helmet Security", "type": "finder"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "vulncheck"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-31T18:50:46.454502Z", "id": "CVE-2026-82021", "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": "2026-08-31T18:50:59.520Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-82021", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-08-27T21:39:20.459Z", "datePublished": "2026-08-28T18:50:38.180Z", "dateUpdated": "2026-08-31T18:50:59.520Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-08-29T11:48:19.100Z"}, "title": "Hermes Agent 0.18.2 < 0.19.0 MCP Catalog Supply Chain RCE via Mutable Branch Reference", "descriptions": [{"lang": "en", "value": "Hermes Agent 0.18.2 prior to 0.19.0 contains a supply chain vulnerability in its bundled MCP catalog that allows a remote attacker to execute arbitrary code by compromising a third-party upstream repository referenced via a mutable branch rather than a pinned commit SHA. An attacker who compromises the upstream repository can propagate malicious code to every host that installs the affected catalog entry, with no further action required by the operator."}], "tags": ["x_open-source"], "datePublic": "2026-07-14T00:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-494", "description": "Download of Code Without Integrity Check", "type": "CWE"}]}], "affected": [{"defaultStatus": "affected", "vendor": "NousResearch", "product": "hermes-agent", "packageURL": "pkg:github/NousResearch/hermes-agent", "repo": "https://github.com/NousResearch/hermes-agent", "versions": [{"status": "affected", "version": "0.18.2", "versionType": "semver", "lessThan": "0.19.0"}, {"status": "affected", "version": "2026.7.7.2", "versionType": "custom", "lessThan": "2026.7.20"}]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "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:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "version": "3.1", "baseSeverity": "HIGH", "baseScore": 8.3, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H"}}], "references": [{"url": "https://github.com/NousResearch/hermes-agent/releases/tag/v2026.7.20", "name": "Hermes Agent v2026.7.20 Release Notes", "tags": ["release-notes"]}, {"url": "https://github.com/NousResearch/hermes-agent/pull/64463", "name": "Pull Request", "tags": ["issue-tracking", "patch"]}, {"url": "https://github.com/NousResearch/hermes-agent/commit/9df5f879b4a5925c0f8f947e7e16ed8e845932c3", "name": "Patch Commit", "tags": ["patch"]}, {"url": "https://www.vulncheck.com/advisories/hermes-agent-mcp-catalog-supply-chain-rce-via-mutable-branch-reference", "tags": ["third-party-advisory"]}], "credits": [{"lang": "en", "value": "Zubair Ashraf (@zashraf1337), Helmet Security", "type": "finder"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "vulncheck"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-82021", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-08-31T18:50:46.454502Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-31T18:50:52.473Z"}}]}}

{"affected": [{"affectedData": [{"defaultStatus": "affected", "packageURL": "pkg:github/NousResearch/hermes-agent", "product": "hermes-agent", "repo": "https://github.com/NousResearch/hermes-agent", "vendor": "NousResearch", "versions": [{"lessThan": "0.19.0", "status": "affected", "version": "0.18.2", "versionType": "semver"}, {"lessThan": "2026.7.20", "status": "affected", "version": "2026.7.7.2", "versionType": "custom"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Hermes Agent 0.18.2 prior to 0.19.0 contains a supply chain vulnerability in its bundled MCP catalog that allows a remote attacker to execute arbitrary code by compromising a third-party upstream repository referenced via a mutable branch rather than a pinned commit SHA. An attacker who compromises the upstream repository can propagate malicious code to every host that installs the affected catalog entry, with no further action required by the operator."}], "id": "CVE-2026-82021", "lastModified": "2026-09-08T20:23:49.880", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.3, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 6.0, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "NONE", "attackVector": "NETWORK", "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": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/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": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-82021", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-31T18:50:46.454502Z", "version": "2.0.3"}}]}, "published": "2026-08-28T20:20:14.470", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/NousResearch/hermes-agent/commit/9df5f879b4a5925c0f8f947e7e16ed8e845932c3"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/NousResearch/hermes-agent/pull/64463"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/NousResearch/hermes-agent/releases/tag/v2026.7.20"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/hermes-agent-mcp-catalog-supply-chain-rce-via-mutable-branch-reference"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-494"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0.18.2,0.19.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[2026.7.7.2,2026.7.20)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "hermes-agent", "source": "cna", "vendor": "NousResearch"}, "product": "hermes-agent", "vendor": "nousresearch"}], "created": "2026-08-28T21:30:05.065988+00:00", "updated": "2026-08-28T22:30:17.714327+00:00", "vendors": ["nousresearch", "nousresearch$PRODUCT$hermes-agent"]}