SGLang through 0.5.19 in prefill/decode disaggregation mode contains an unauthenticated PUT /route endpoint on the prefill bootstrap service that allows attackers to poison the KV transfer routing table. Attackers can supply arbitrary rank_ip and rank_port values to redirect decode workers to attacker-controlled endpoints, causing denial of service or disclosure of KV transfer metadata including session identifiers and tensor-parallel topology parameters.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact Low

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
sgl-project sglang unaffected
Version Status Constraints
0 affected ≤ 0.5.19

No data.

No data.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/sgl-project/sglang cve-icon cve-icon
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/common/conn.py#L1716-L1718 cve-icon cve-icon
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/common/conn.py#L1736-L1810 cve-icon cve-icon
https://github.com/sgl-project/sglang/issues/39400 cve-icon cve-icon
https://www.vulncheck.com/advisories/sglang-through-0.5.19-unauthenticated-route-poisoning-via-put-endpoint cve-icon cve-icon
History

Thu, 17 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 17 Sep 2026 14:00:00 +0000

Type Values Removed Values Added
Description SGLang through 0.5.19 in prefill/decode disaggregation mode contains an unauthenticated PUT /route endpoint on the prefill bootstrap service that allows attackers to poison the KV transfer routing table. Attackers can supply arbitrary rank_ip and rank_port values to redirect decode workers to attacker-controlled endpoints, causing denial of service or disclosure of KV transfer metadata including session identifiers and tensor-parallel topology parameters.
Title SGLang through 0.5.19 Unauthenticated Route Poisoning via PUT endpoint
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'}

cvssV4_0

{'score': 8.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-17T19:21:12.309Z

Reserved: 2026-09-17T13:23:59.248Z

Link: CVE-2026-92972

cve-icon Vulnrichment

Updated: 2026-09-17T19:15:52.005Z

cve-icon NVD

Status : Received

Published: 2026-09-17T14:18:03.347

Modified: 2026-09-17T20:18:59.850

Link: CVE-2026-92972

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses