Medium severity · published Aug 13, 2026
CVE-2026-73555
vLLM: Unauthenticated Internal Path and Username Disclosure via Validation Error Messages
5.3
CVSS
0.4%
EPSS
No
On KEV
Description
vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the validation_exception_handler in vllm/entrypoints/openai/server_utils.py converts FastAPI RequestValidationError objects with str(exc), and sanitize_message in vllm/entrypoints/utils.py does not remove traceback-style file paths, allowing unauthenticated malformed JSON requests to /v1/chat/completions, /v1/completions, /tokenize, and /detokenize to disclose the OS username, home and virtual-environment paths, Python version, internal package structure, line numbers, and endpoint handler names. This issue is fixed in version 0.26.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
VL
vllm · vllm-project
< 0.26.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73555
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73555
Patch
https://github.com/vllm-project/vllm/commit/e87521626febe2763f997691d1599de4175f4324
Issue Tracking
https://github.com/vllm-project/vllm/pull/46415
Release Notes
https://github.com/vllm-project/vllm/releases/tag/v0.26.0
Mitigation
https://github.com/vllm-project/vllm/security/advisories/GHSA-hwrm-c4cx-rf4j
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