{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "0.36.1"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "37faf2f24724370483b1819b0921c899791bedc7"
            }
          ],
          "repo": "https://github.com/headroomlabs-ai/headroom",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-639"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77776.json"
  },
  "details": "Headroom's LLM proxy derives the memory owner from the x-headroom-user-id request header. The header is read directly at several points in headroom/proxy/handlers/openai.py, including the chat completion and websocket paths, and nothing binds the value to the caller. A client can therefore name another user's identifier and read or write that user's stored LLM memory. The fix introduces a single resolve_memory_identity seam in headroom/proxy/identity.py that honors the header only for loopback or allowlisted callers and otherwise binds the identity to the proxy-token fingerprint or the operating system user. The pip console script binds 127.0.0.1 by default, but the reference docker-compose.yml ships --host 0.0.0.0 with published ports and no required HEADROOM_PROXY_TOKEN, which the server itself warns about at startup, so a deployment following the shipped compose exposes the affected data-plane routes to the network without authentication.",
  "id": "CVE-2026-77776",
  "modified": "2026-09-11T03:30:45.633198688Z",
  "published": "2026-08-21T11:22:51.779Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://pypi.org"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77776.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77776"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/headroom-proxy-treats-the-client-supplied-x-headroom-user-id-header-as-an-authenticated-identity"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/headroomlabs-ai/headroom/pull/2207"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/headroomlabs-ai/headroom"
    },
    {
      "type": "ARTICLE",
      "url": "https://github.com/headroomlabs-ai/headroom/blob/v0.29.0/headroom/proxy/handlers/openai.py"
    },
    {
      "type": "ARTICLE",
      "url": "https://github.com/headroomlabs-ai/headroom/blob/v0.36.1/headroom/proxy/identity.py"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Headroom Proxy Treats the Client-Supplied x-headroom-user-id Header as an Authenticated Identity"
}