Vulnerability in vllm (CVE-2026-105756)
Summary
Vulnerability in vllm (CVE-2026-105756). Risk of unauthorized operations or information disclosure. Exploitable via vllm. Mitigation: upgrade to 0.30.0 or later.
Original description
The description as published by the source.
Affected
- Ecosystem / package: pip /
vllm - Affected versions: vLLM ≤ 0.25.1 (confirmed on 0.25.1, commit
752a3a504485). The lower bound predates 0.25.1; maintainers can confirm how far back the loosecache_saltvalidator and unguarded scheduling-path lookup reach.
Summary
vLLM's OpenAI-compatible request models (Completions, Chat Completions, Responses) accept a client-supplied cache_salt field and validate it only as "must be a non-empty string" — no character or length restrictions. On a deployment with the built-in LMCache-MP KV connector enabled, that value is stored verbatim on the request tracker and forwarded unguarded as a keyword argument into the scheduler's per-step cache lookup. The downstream LMCache library applies a stricter check in IPCCacheServerKey.__post_init__, which raises ValueError for any cache_salt containing @, /, \, or NUL (or longer than 128 characters).
Neither the LMCache-MP connector lookup call site nor Scheduler.schedule() wraps that call in a request-scoped try/except, so the ValueError propagates uncaught into EngineCore's top-level handler, which treats any uncaught exception as fatal and kills the whole engine process. A single publicly reachable request with, for example, cache_salt="/" therefore takes down the engine for all concurrent users. vLLM's boundary validator is looser than the downstream co…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-105756 has been found in vllm.
Attackers can target a specific entry point like vllm over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade vllm to 0.30.0 or later.
If unsure, ask your IT team or search "vllm CVE-2026-105756" on the vendor's site.
CVE-2026-105756 (vllm) — CWE-20 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: vllm / cache_salt / IPCCacheServerKey.__post_init__ / ValueError
Patched: 0.30.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-20) exists in vllm. Attackers reach the vulnerable code path via vllm.
Check the vendor advisory for the affected versions of vllm. Attack surface: vllm / cache_salt / IPCCacheServerKey.__post_init__ / ValueError.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 0.30.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'vllm' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'vllm' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
vllmを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade vllm to 0.30.0ステージング環境で 0.30.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。