# CVE-2026-129356: vllm-project vllm Common Prefix single_type_kv_cache_manager.py race condition

Status: published. Published: 2026-11-15. Updated: 2026-11-15.

A vulnerability was found in vllm-project vllm 0.30.0/0.31.0. This vulnerability affects unknown code of the file single_type_kv_cache_manager.py of the component Common Prefix Handler. The manipulation results in race condition. The attack may be performed from remote. Attacks of this nature are highly complex. It is stated that the exploitability is difficult. The exploit has been made public and could be used. Upgrading to version 0.32.0 is able to resolve this issue. The patch is identified as e687a251bb056fa527846633f7a1b0a6c0f42374. You should upgrade the affected component.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulDB) — https://github.com/vllm-project/vllm/pull/61126
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulDB) — https://github.com/vllm-project/vllm/commit/e687a251bb056fa527846633f7a1b0a6c0f42374
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulDB) — https://github.com/vllm-project/vllm/releases/tag/v0.32.0

## Affected products and versions

- vllm-project / vllm: 0.30.0 (affected); 0.31.0 (affected); 0.32.0 (unaffected). Source: CNA: VulDB

## Severity and prioritization

- CVSS 4.0: 2.3 (low); CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P; source: CNA: VulDB

- CVSS 3.1: 5 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C; source: CNA: VulDB

- CVSS 3.0: 5 (medium); CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C; source: CNA: VulDB

- CVSS 2.0: 4.6 (medium); AV:N/AC:H/Au:S/C:P/I:P/A:P/E:POC/RL:OF/RC:C; source: CNA: VulDB

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-362

## Exploit evidence

- exploit: https://github.com/vllm-project/vllm/issues/61673 (CNA: VulDB)

## References

- https://vuldb.com/vuln/437419 (CNA: VulDB; vdb-entry)

- https://vuldb.com/vuln/437419/cti (CNA: VulDB; signature, permissions-required)

- https://vuldb.com/cve/CVE-2026-129356 (CNA: VulDB; third-party-advisory)

- https://vuldb.com/submit/1043823 (CNA: VulDB; third-party-advisory)

- https://github.com/vllm-project/vllm/issues/61673 (CNA: VulDB; exploit, issue-tracking)

- https://github.com/vllm-project/vllm/pull/61126 (CNA: VulDB; issue-tracking, patch)

- https://github.com/vllm-project/vllm/commit/e687a251bb056fa527846633f7a1b0a6c0f42374 (CNA: VulDB; patch)

- https://github.com/vllm-project/vllm/releases/tag/v0.32.0 (CNA: VulDB; patch)

- https://github.com/vllm-project/vllm/ (CNA: VulDB; product)

## Provenance

- CNA: VulDB: https://www.cve.org/CVERecord?id=CVE-2026-129356; retrieved 2026-11-15; source updated 2026-11-15

Revision: 58b3f1ef891ca07ef2051d6420d2ba53e2d216ec4768ac7ce069ec71ab983f4f

Canonical: https://y2.dev/cve/CVE-2026-129356

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