vLLM is vulnerable to timing attack at bearer auth
High7.5CVE-2025-59425 · Published Oct 7, 2025 · updated Sep 10, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| vllm PyPI | < 0.11.0 | 0.11.0 |
Details and references
### Summary The API key support in vLLM performed validation using a method that was vulnerable to a timing attack. This could potentially allow an attacker to discover a valid API key using an approach more efficient than brute force. ### Details https://github.com/vllm-project/vllm/blob/4b946d693e0af15740e9ca9c0e059d5f333b1083/vllm/entrypoints/openai/api_server.py#L1270-L1274 API key validation used a string comparison that will take longer the more characters the provided API key gets correct. Data analysis across many attempts can allow an attacker to determine when it finds the next correct character in the key sequence. ### Impact Deployments relying on vLLM's built-in API key validation are vulnerable to authentication bypass using this technique.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-385
- Also known as
- CVE-2025-59425, PYSEC-2026-2026
- github.com/vllm-project/vllm/security/advisories/GHSA-wr9h-g72x-mwhm
- nvd.nist.gov/vuln/detail/CVE-2025-59425
- github.com/vllm-project/vllm/commit/ee10d7e6ff5875386c7f136ce8b5f525c8fcef48
- github.com/advisories/GHSA-wr9h-g72x-mwhm
- github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2026-2026.yaml
- github.com/vllm-project/vllm
- github.com/vllm-project/vllm/blob/4b946d693e0af15740e9ca9c0e059d5f333b1083/vllm/entrypoints/openai/api_server.py#L1270-L1274
- github.com/vllm-project/vllm/releases/tag/v0.11.0
- pypi.org/project/vllm
More vLLM advisories
All vLLM| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Oct 72025 | vLLM: Resource-Exhaustion (DoS) through Malicious Jinja Template in OpenAI-Compatible Server CVE-2025-61620Medium6.5fixed in 0.11.0 | Medium6.5 | 0.11.0 |
| Oct 72025 | vLLM is vulnerable to Server-Side Request Forgery (SSRF) through `MediaConnector` class CVE-2025-6242High7.1fixed in 0.11.0 | High7.1 | 0.11.0 |
| Nov 202025 | vLLM deserialization vulnerability leading to DoS and potential RCE CVE-2025-62164High8.8fixed in 0.11.1 | High8.8 | 0.11.1 |
| Nov 202025 | vLLM vulnerable to DoS with incorrect shape of multimodal embedding inputs CVE-2025-62372High6.5fixed in 0.11.1 | High6.5 | 0.11.1 |
| Nov 202025 | vLLM vulnerable to DoS via large Chat Completion or Tokenization requests with specially crafted `chat_template_kwargs` CVE-2025-62426Medium6.5fixed in 0.11.1 | Medium6.5 | 0.11.1 |
| Aug 212025 | vLLM has remote code execution vulnerability in the tool call parser for Qwen3-Coder CVE-2025-9141High8.8fixed in 0.10.1.1 | High8.8 | 0.10.1.1 |