CVE-2026-7141 Details
Description
A vulnerability was found in vLLM up to 0.19.0. The affected element is the function has_mamba_layers of the file vllm/v1/kv_cache_interface.py of the component KV Block Handler. Performing a manipulation results in uninitialized resource. It is possible to initiate the attack remotely. The attack is considered to have high complexity. The exploitability is described as difficult. The exploit has been made public and could be used. The existence of this vulnerability is still disputed at present. The proposed patch did not fix the issue. A 3rd party explains: "The divergence could be explained by a benign and expected vLLM behavior where vLLM server could group concurrent requests together resulting in different input shapes based on varying request arrival time. The differences in grouped input shapes could call different kernels with could produce difference results due to rounding and differences in order of operations. There is an environment variable VLLM_BATCH_INVARIANT=1 for users that desire to have deterministic output with temperature 0.0."
A vulnerability exists in vllm versions through 0.19.0 within the KV Block Handler component. The issue arises in the 'has_mamba_layers' function of 'vllm/v1/kv_cache_interface.py', where the block allocator returns GPU KV cache blocks to the free pool without clearing their contents. This flaw allows a subsequent request to access stale data from a previous one, disrupting the expected data flow. The vulnerability can be exploited remotely, particularly in multi-tenant environments, where it could cause one user's data to inadvertently influence another's. The issue has been publicly disclosed and is challenging to exploit, but a proof-of-concept exploit is available.
Users are advised to update to vllm version 0.19.1 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 27, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/vllm-project/vllm/issues/39146 | [email protected] | Issue Tracking |
| https://github.com/vllm-project/vllm/issues/39146#issue-4215090365 | [email protected] | Issue Tracking |
| https://vuldb.com/cve/CVE-2026-7141 | [email protected] | |
| https://vuldb.com/submit/801297 | [email protected] | Third Party AdvisoryVDB Entry |
| https://vuldb.com/vuln/359740 | [email protected] | Third Party AdvisoryVDB Entry |
| https://vuldb.com/vuln/359740/cti | [email protected] | Permissions Required |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-908 | Use of Uninitialized Resource | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| vllm vllm | <= 0.19.0 |
CPE
Remediation
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Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 25, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 1, 2026 | Initial Analysis | [email protected] |
| Apr 29, 2026 | Data Remediation | [email protected] |
| Apr 27, 2026 | New CVE Received | [email protected] |