{
    "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": "2026-08-28T19:59:12.130Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
                "shortName": "VulnCheck",
                "dateUpdated": "2026-08-28T19:59:12.130Z"
            },
            "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": "Release Notes",
                    "tags": [
                        "release-notes"
                    ]
                },
                {
                    "url": "https://github.com/NousResearch/hermes-agent/pull/64463",
                    "name": "Pull Request",
                    "tags": [
                        "issue-tracking"
                    ]
                },
                {
                    "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"
            }
        }
    }
}