CVE-2026-4963 — huggingface smolagents Incomplete Fix CVE-2025-9959 local_python_executor.py evaluate_with code injection
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.7% (30-day exploitation probability)+8
- Technical severity (critical)+10
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Huggingface Smolagents).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Huggingface | Smolagents | version 1.25.0-dev0 | Vulnerable | NIST National Vulnerability Database |
| Huggingface | Smolagents | version 1.25.0.dev0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.3 | CVSS 4.0 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 2.1 | CVSS 4.0 | Low | — | — | cna@vuldb.com via NIST National Vulnerability Database |
| 10.0 | CVSS 3.1 | Critical | 3.9 | 6.0 | nvd@nist.gov via NIST National Vulnerability Database |
| 6.3 | CVSS 3.1 | Medium | 2.8 | 3.4 | cna@vuldb.com via NIST National Vulnerability Database |
| 6.3 | CVSS 3.1 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 6.3 | CVSS 3.0 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 7.5 | CVSS 2.0 | High | 10.0 | 6.4 | cna@vuldb.com via NIST National Vulnerability Database |
| 7.5 | CVSS 2.0 | High | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.73%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · huggingface/smolagents
- SSVC assessment updated
- Record published
- CVSS changed · 10.0
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
7 on the record
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-2654 huggingface smolagents LocalPythonExecutor requests.post server-side request forgery Feb 18, 2026
- Critical CVE-2025-14931 Hugging Face smolagents Remote Python Executor Deserialization of Untrusted Data Remote Code Execution Vulnerability Dec 23, 2025
- Medium CVE-2025-11844 XPath Injection in Hugging Face Smolagents search_item_ctrl_f Function Oct 22, 2025
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-4963 is "huggingface smolagents Incomplete Fix CVE-2025-9959 local_python_executor.py evaluate_with code injection", rated Critical. It affects Smolagents (Huggingface); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 10.0 describes technical severity. EPSS 0.73% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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