Staging Environment: Content and features may be unstable or change without notice.
Advisory details: pypa / vllm/PYSEC-2026-3996
Advisory ID pypa/vllm/PYSEC-2026-3996
Aliases CVE-2026-93436
PYSEC-2026-3996
Summary vLLM through 0.29.0 fails to properly clean up decode-side metadata for rejected inference requests in prefill/decode disaggregated deployments. Remote attackers can submit requests with max_tokens=0 to exhaust decode-worker memory without bound until the worker restarts.
Status Published
Exploitability 0.5
Weighted Severity 7.8
Risk 3.9
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv4 8.7 https://github.com/pypa/advisory-database/blob/main/vulns/vllm/PYSEC-2026-3996.yaml
Reference id Reference type URL
https://github.com/vllm-project/vllm
55677 Bug https://github.com/vllm-project/vllm/pull/55677
push_worker.py#L162-L181 Other https://github.com/vllm-project/vllm/blob/v0.29.0/vllm/distributed/kv_transfer/kv_connector/v1/nixl/push_worker.py#L162-L181
vllm-through-0.29.0-memory-exhaustion-via-rejected-requests Advisory https://www.vulncheck.com/advisories/vllm-through-0.29.0-memory-exhaustion-via-rejected-requests
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Found at https://github.com/pypa/advisory-database/blob/main/vulns/vllm/PYSEC-2026-3996.yaml
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.