CVE-2026-4963: PYSEC-2026-3066 - Hugging Face Smolagents has an Injection issue

CVE-2026-4963 · Severity: medium · CVSS 6.3 · Published 2026-03-27

A weakness has been identified in huggingface smolagents 1.25.0.dev0. This affects the function evaluate_augassign/evaluate_call/evaluate_with of the file src/smolagents/local_python_executor.py of the component Incomplete Fix CVE-2025-9959. This manipulation causes code injection. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Technologies: smolagents (PyPI). Vendors: Huggingface, PyPI.

Quick answers

Is CVE-2026-4963 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-4963 being exploited in the wild.
How severe is CVE-2026-4963?
Medium severity, with a CVSS score of 6.3, published 27 March 2026.
Which products and versions are affected?
smolagents (PyPI) ECOSYSTEM:introduced=0,last_affected=1.25.0.dev0.
Is there a fix for CVE-2026-4963?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-4963?
Check whether you run Huggingface Smolagents or smolagents (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

  • Huggingface Smolagents
  • smolagents (PyPI) ECOSYSTEM:introduced=0,last_affected=1.25.0.dev0

Identifiers

  • CVE-2026-4963
  • GHSA-54fq-v6x8-244g
  • PYSEC-2026-3066

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.