Cyber Resilience

CVE-2026-5760

CriticalPublic PoCRCEUpdated

Published: 20 April 2026

Published
20 April 2026
Modified
03 June 2026
KEV Added
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Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0085 53.5th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-5760 is a critical-severity Code Injection (CWE-94) vulnerability in Lmsys Sglang. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 46.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 CM-6 (Configuration Settings) and SI-10 (Information Input Validation).

Deeper analysis

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.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

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().

CWE(s)
CWE-94

Related Threats

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

CVEs Like This One

CVE-2026-3060Same product: Lmsys Sglang
CVE-2026-3059Same product: Lmsys Sglang
CVE-2026-7301Same product: Lmsys Sglang
CVE-2026-7302Same product: Lmsys Sglang
CVE-2026-7304Same product: Lmsys Sglang
CVE-2025-46295Shared CWE-94
CVE-2026-27745Shared CWE-94
CVE-2025-54815Shared CWE-94
CVE-2025-12733Shared CWE-94
CVE-2025-29306Shared CWE-94

Affected Assets

lmsys
sglang
≤ 0.5.11

Mitigating Controls

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.

References