{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77776","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-08-21T11:09:25.553Z","datePublished":"2026-08-21T11:22:51.779Z","dateUpdated":"2026-08-21T21:44:30.707Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-08-21T11:22:51.779Z"},"datePublic":"2026-08-20T00:00:00.000Z","title":"Headroom Proxy Treats the Client-Supplied x-headroom-user-id Header as an Authenticated Identity","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Authorization Bypass Through User-Controlled Key","cweId":"CWE-639","type":"CWE"}]}],"affected":[{"vendor":"Headroom Labs","product":"Headroom","collectionURL":"https://pypi.org","packageName":"headroom-ai","packageURL":"pkg:pypi/headroom-ai","repo":"https://github.com/headroomlabs-ai/headroom","defaultStatus":"unaffected","versions":[{"version":"0","lessThan":"0.36.1","status":"affected","versionType":"semver"},{"version":"0.36.1","status":"unaffected","versionType":"semver"}],"programFiles":["headroom/proxy/handlers/openai.py","headroom/proxy/memory_handler.py","headroom/memory/easy.py"]}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":9.1,"baseSeverity":"CRITICAL"}},{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL"}}],"references":[{"url":"https://github.com/headroomlabs-ai/headroom/pull/2207","tags":["issue-tracking"],"name":"Pull Request #2207 addressing the assessment findings"},{"url":"https://github.com/headroomlabs-ai/headroom/blob/v0.29.0/headroom/proxy/handlers/openai.py","tags":["technical-description"],"name":"Header handling in the OpenAI proxy handler at v0.29.0"},{"url":"https://github.com/headroomlabs-ai/headroom/blob/v0.36.1/headroom/proxy/identity.py","tags":["technical-description"],"name":"resolve_memory_identity seam introduced by the fix"},{"url":"https://github.com/headroomlabs-ai/headroom","tags":["product"]},{"name":"VulnCheck Advisory: Headroom Proxy Treats the Client-Supplied x-headroom-user-id Header as an Authenticated Identity","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/headroom-proxy-treats-the-client-supplied-x-headroom-user-id-header-as-an-authenticated-identity"}],"credits":[{"lang":"en","value":"Gregory Tan (Grg0rry)","type":"finder"}]},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-21T21:18:54.351966Z","id":"CVE-2026-77776","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"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":"2026-08-21T21:44:30.707Z"}}]}}