CVE-2026-7141

vLLM KV Block kv_cache_interface.py has_mamba_layers uninitialized resource

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Published Apr 27, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
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."

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-x368-4g9h-fvv4 vLLM makes Use of Uninitialized Resource
History
Type Values Removed Values Added
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 patch is named 1ad67864c0c20f167929e64c875f5c28e1aad9fd. To fix this issue, it is recommended to deploy a patch. 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."
Title vllm KV Block kv_cache_interface.py has_mamba_layers uninitialized resource vLLM KV Block kv_cache_interface.py has_mamba_layers uninitialized resource
References
Metrics cvssV2_0

{'score': 5.1, 'vector': 'AV:N/AC:H/Au:N/C:P/I:P/A:P/E:POC/RL:OF/RC:C'}

cvssV3_0

{'score': 5.6, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C'}

cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C'}

 cvssV2_0

{'score': 5.1, 'vector': 'AV:N/AC:H/Au:N/C:P/I:P/A:P/E:POC/RL:U/RC:UR'}

cvssV3_0

{'score': 5.6, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:U/RC:R'}

cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:U/RC:R'}
Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Moderate
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}
Type Values Removed Values Added
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 patch is named 1ad67864c0c20f167929e64c875f5c28e1aad9fd. To fix this issue, it is recommended to deploy a patch.
Title vllm KV Block kv_cache_interface.py has_mamba_layers uninitialized resource
First Time appeared Vllm
Vllm vllm
Weaknesses CWE-908
CPEs cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*
Vendors & Products Vllm
Vllm vllm
References
Metrics cvssV2_0

{'score': 5.1, 'vector': 'AV:N/AC:H/Au:N/C:P/I:P/A:P/E:POC/RL:OF/RC:C'}

cvssV3_0

{'score': 5.6, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C'}

cvssV3_1

{'score': 5.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P'}
Weaknesses

Sources

Status
PUBLISHED
Assigner
VulDB
Published
Updated
Aug 25, 2026, 7:07 PM
Reserved
Apr 26, 2026, 7:38 PM

View source JSON

Updated
Apr 27, 2026, 5:41 PM

JSON

Status
Modified
Published
Apr 27, 2026, 5:16 PM
Modified
Nov 11, 2026, 11:10 PM

View source JSON

Severity
Moderate
Public date
Apr 27, 2026, 4:45 PM

View source Bugzilla JSON

Updated
Aug 26, 2026, 6:45 AM

JSON