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MEDIUM

sgl-project SGLang HuggingFace Transformer hf_transformers_utils.py get_tokenizer code injection

Published May 2, 2026

Description

A vulnerability was detected in sgl-project SGLang up to 0.5.9. Impacted is the function get_tokenizer of the file python/sglang/srt/utils/hf_transformers_utils.py of the component HuggingFace Transformer Handler. The manipulation of the argument trust_remote_code with the input False as part of Boolean results in code injection. The attack can be executed remotely. A high complexity level is associated with this attack. The exploitability is considered difficult. In get_tokenizer(), when the caller passes trust_remote_code=False and HuggingFace transformers v5 returns a TokenizersBackend instance (the generic fallback for tokenizer classes not in the registry), SGLang silently re-invokes AutoTokenizer.from_pretrained with trust_remote_code=True, overriding the caller's explicit security setting. A model repository containing a malicious tokenizer.py referenced via auto_map in tokenizer_config.json will execute arbitrary Python in the SGLang process during this second call. No log line or warning is emitted. The override affects all current SGLang versions because transformers==5.3.0 is pinned in pyproject.toml. Both tokenizer_mode="auto" and tokenizer_mode="slow" are affected. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Affected products

Remediation

No remediation recorded yet.

References (7)

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED
Assigner VulDB
Published May 2, 2026
Updated May 5, 2026
Reserved May 2, 2026

CISA Vulnrichment

Updated May 5, 2026

NVD

Status Deferred
Modified Jun 17, 2026

Red Hat

No data

ENISA EUVD

Assigner VulDB
Published May 2, 2026
Updated May 5, 2026