TC-2026-0009 · NPM · MCP

[email protected]

CVE-2026-4496: passes unsanitized git ref and branch strings directly into shell execution, enabling RCE when an agent inspects an untrusted repository.

Primary advisory (NVD / GitHub Security Advisory) Back to all 66 records

Signed ledger verdict

TC-2026-0009
Known bad (exit 2) npm:[email protected]

IOC & scope: npm:[email protected] (CVE-2026-4496). Verified by human review and signed into the CC-BY 4.0 OSV v1.6.0 feed.

Credited finder
NVD / GitHub Security Advisory ↗
Recorded timestamp
2026-04-18
Canonical SHA-256
4eac93eb4f00f4e0…
Local hook action
Block (exit 2)
Run live in Counter Workbench

Signed in /feed.json (.sig).

01 8-Vector Capability X-Ray (ABOM) & OWASP Agentic Crosswalk

Deterministic capability profile and taxonomy mapping.

Every artifact in the threat.cafe ledger is profiled across eight execution vectors and mapped to the OWASP Top 10 for Agentic Applications (ASI01-ASI10) and Agentic Skills & Tools (AST01-AST10).

8-Vector Capability X-Ray (ABOM)

  1. 1. Filesystem
    Sensitive paths touched: .git/config, .git/hooks/*
  2. 2. Environment
    Variables harvested: None observed
  3. 3. Network
    Outbound egress domains: None observed
  4. 4. Subprocess
    Process execution primitives: execSync('git checkout ' + ref)
  5. 5. Lifecycle
    Install / startup hooks: None observed
  6. 6. OAuth / MCP
    Declared scopes: None observed
  7. 7. Obfuscation
    Encoding / steganography: None observed
  8. 8. Provenance
    Attestation status: vulnerable_release_cve_2026_4496

Governance & detector mapping

  1. OWASP Agentic ASI (2026): ASI01 (Agent Goal Hijack), ASI02 (Tool Misuse & Exploitation), ASI05 (Unexpected Code Execution (RCE))
  2. OWASP Agentic AST (2026): AST02 (Tool & Skill Injection), AST05 (Sandbox Escape & Local Execution)
  3. Deterministic rules matched: RULE_05_PROMPT_EXFIL_SHELL

Version scoping & related records

  • No other versions of this package are currently listed on the board. Unlisted versions evaluate to unknown under local policy.yml.

Local CLI verification

$ threat-cafe-hook check "npm:[email protected]"
[threat.cafe] known_bad: npm:[email protected] (TC-2026-0009)
  Reason: CVE-2026-4496: passes unsanitized git ref and branch strings directly into shell execution
  Source: https://nvd.nist.gov/vuln/detail/CVE-2026-4496 (credited to NVD / GitHub Security Advisory)

OSV v1.6.0 machine-readable record

Included in /feed.json under CC-BY 4.0 license and verified by /feed.json.sig.

{
  "schema_version": "1.6.0",
  "id": "TC-2026-0009",
  "modified": "2026-04-18T10:30:00Z",
  "published": "2026-04-18T10:30:00Z",
  "summary": "CVE-2026-4496: passes unsanitized git ref and branch strings directly into shell execution, enabling RCE when an agent inspects an untrusted repository.",
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "git-mcp-server"
      },
      "versions": [
        "1.1.0"
      ]
    }
  ],
  "credits": [
    {
      "name": "NVD / GitHub Security Advisory",
      "type": "FINDER"
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4496"
    },
    {
      "type": "WEB",
      "url": "https://threat.cafe/incidents/tc-2026-0009/"
    }
  ],
  "database_specific": {
    "target": "npm:[email protected]",
    "kind": "mcp",
    "verdict": "known_bad",
    "ioc": "npm:[email protected] (CVE-2026-4496)",
    "artifact_sha256": "4eac93eb4f00f4e077eff75d0f8f86f3275ff68235d68bbfd8cba031b67f152e",
    "owasp_asi": [
      "ASI01",
      "ASI02",
      "ASI05"
    ],
    "owasp_ast": [
      "AST02",
      "AST05"
    ],
    "rules_matched": [
      "RULE_05_PROMPT_EXFIL_SHELL"
    ],
    "abom": {
      "fs_sensitive": [
        ".git/config",
        ".git/hooks/*"
      ],
      "env_harvest": [],
      "net_egress": [],
      "proc_exec": [
        "execSync('git checkout ' + ref)"
      ],
      "install_hooks": [],
      "oauth_scopes": [],
      "obfuscation": [],
      "provenance": "vulnerable_release_cve_2026_4496"
    },
    "license": "CC-BY-4.0",
    "record_digest": "sha256:7bdfc782cdf35107e5ba6200867a1760affcb02ae1a4a24ab8485bd3b948dfd6",
    "release_signature_url": "https://threat.cafe/feed.json.sig"
  }
}

Have additional IOCs or a maintainer remediation update for TC-2026-0009?

Maintainer disputes and version-scoping updates are reviewed by a human within our 48-hour dispute SLA.

Submit update or dispute Read 48h dispute policy