Pickle Deserialization Vulnerability in SGLang by Vicon
CVE-2026-86793

9.8CRITICAL

Key Information:

Vendor

Sglang

Status
Sglang
Vendor
CVE Published:
11 September 2026

What is CVE-2026-86793?

The SGLang software has a critical security flaw that allows unauthenticated users to exploit a pickle deserialization issue via the /update_weights_from_tensor endpoint. This occurs when authentication keys are not implemented, thus bypassing SafeUnpickler policies. Attackers can leverage builtins.import and builtins.getattr to execute arbitrary code on vulnerabilities within the system, posing significant risks to application integrity and data security.

Affected Version(s)

SGLang 0 <= 0.5.18

References

https://vicone.com/blog/cve-2026-86793-sglang-bypass-coul...
https://github.com/sgl-project/sglang/tree/main

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.