- Description
- 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.
- Source
- disclosure@vulncheck.com
- NVD status
- Received
CVSS 4.0
- Type
- Secondary
- Base score
- 9.3
- Impact score
- -
- Exploitability score
- -
- Vector string
- 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/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
- Severity
- CRITICAL
CVSS 3.1
- Type
- Secondary
- Base score
- 9.1
- Impact score
- 5.2
- Exploitability score
- 3.9
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Severity
- CRITICAL
- disclosure@vulncheck.com
- CWE-639
- Hype score
- Not currently trending
CVE-2026-77776: Headroom-LLM-Proxy erlaubt fremden Zugriff auf gespeicherten Chat-Speicher KurzfassungBei Headroom liegt eine kritische Schwachstelle vor. Der LLM-Proxy übernimmt die Identität eines Nutzers direkt aus einem HTTP-Header und p https://t.co/YmI5XGdZBI
@cybsecuritynews
23 Aug 2026
5 Impressions
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CVE-2026-77776 (CVSS 9.1): Headroom's LLM proxy (https://t.co/1Ym4mwuRlD) treats x-headroom-user-id as memory owner — no bind. Name another user's id → read/write stored LLM memory. Fixed in 0.36.1. CVE-2026-59279 + CVE-2026-64849 — no bind / no cap / no IP pin. #CVE #Pytho
@Innora_sg
21 Aug 2026
25 Impressions
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