Vulnerability · Published Sep 17, 2026 · Assigned by VulnCheck

CVE-2026-92972SGLang through 0.5.19 Unauthenticated Route Poisoning via PUT endpoint

High 8.6

In plain English

A high-severity missing authentication in sglang from sgl-project. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities).

Severity (CVSS 3.1)8.6High

Exploit odds (30 days)0.5%top 59.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
sgl-project	sglang	0 – through 0.5.19

Weakness: CWE-306 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

References

GitHub Issue #39400 issue-tracking
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/common/conn.py#L1736-L1810 technical-description
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/common/conn.py#L1716-L1718 technical-description
https://github.com/sgl-project/sglang product
VulnCheck Advisory: SGLang through 0.5.19 Unauthenticated Route Poisoning via PUT endpoint third-party-advisory