Cyber Posture

CVE-2026-5760

Critical

Published: 20 April 2026

Published
20 April 2026
Modified
20 April 2026
KEV Added
—
Patch
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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0032 55.4th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

SGLang's reranking endpoint (/v1/rerank) achieves Remote Code Execution (RCE) when a model file containing a malcious tokenizer.chat_template is loaded, as the Jinja2 chat templates are rendered using an unsandboxed jinja2.Environment().

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match
prevent

Validates and sanitizes chat_template content from loaded model files to prevent code injection via malicious Jinja2 templates in the reranking endpoint.

CM-6 Configuration Settings good match
prevent

Enforces secure configuration settings for the Jinja2 environment to enable sandboxing, directly preventing RCE from unsandboxed template rendering.

SI-2 Flaw Remediation good match
prevent

Remediates the specific flaw in SGLang's reranking endpoint by applying vendor patches or updates that address unsandboxed Jinja2 rendering.

Security SummaryAI

CVE-2026-5760, published on 2026-04-20, is a critical vulnerability (CVSS 9.8, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) affecting SGLang's reranking endpoint (/v1/rerank). It enables remote code execution (RCE) when a model file containing a malicious tokenizer.chat_template is loaded, as Jinja2 chat templates are rendered using an unsandboxed jinja2.Environment(). The issue is classified under CWE-94 (code injection).

An unauthenticated attacker with network access can exploit the vulnerability with low attack complexity and no user interaction. By triggering the loading of a model file with a malicious chat template via the reranking endpoint, the attacker achieves arbitrary remote code execution, compromising confidentiality, integrity, and availability to a high degree.

Mitigation details are available in related advisories, including the GitHub proof-of-concept repository at https://github.com/Stuub/SGLang-0.5.9-RCE and the CERT vulnerability note at https://www.kb.cert.org/vuls/id/915947.

Details

CWE(s)
CWE-94

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1221 Template Injection Stealth
Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts.
attack.mitre.org →
Why these techniques?

CVE enables unauthenticated RCE via exploitation of public-facing reranking endpoint (T1190) through code injection in unsandboxed Jinja2 chat templates (T1221).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References