CVE-2026-73555: vLLM: Unauthenticated Internal Path and Username Disclosure via Validation Error Messages
When the vLLM API receives a malformed request (e.g., invalid JSON or missing required fields), FastAPI raises a Pydantic RequestValidationError. The validation_exception_handler in vllm/entrypoints/openai/server_utils.py converts this exception to a string via str(exc), which includes the internal file path and line number of the handler function. The existing sanitize_message() function in vllm/entrypoints/utils.py strips memory addresses (e.g., 0x7f...) but does not strip File "...", line X patterns. The result is a user-facing HTTP response that leaks internal system information.
References
- github.com/advisories/GHSA-hwrm-c4cx-rf4j
- github.com/vllm-project/vllm/commit/e87521626febe2763f997691d1599de4175f4324
- github.com/vllm-project/vllm/pull/46415
- github.com/vllm-project/vllm/releases/tag/v0.26.0
- github.com/vllm-project/vllm/security/advisories/GHSA-hwrm-c4cx-rf4j
- nvd.nist.gov/vuln/detail/CVE-2026-73555
Code Behaviors & Features
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