SEPTEMBER 17, 2026
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Case File

CVE-2026-77776

CRITICAL · CVSS 9.1 EPSS 0.34% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-21 · Last synced 2026-09-17

CyberRota Analysis

AI-Generated

The vulnerability affects Docker deployments of Headroom's LLM proxy, allowing unauthorized users to access or manipulate another user's stored LLM memory by exploiting the x-headroom-user-id request header. This critical flaw can lead to significant data breaches, as it permits arbitrary memory access without proper authentication. Organizations using Docker with Headroom should prioritize patching this vulnerability to secure sensitive user data and prevent unauthorized access.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-77776
Severity
CRITICAL
CVSS
9.1
EPSS
0.34%
Docker

Original NVD 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.