CVE-2026-31239

Description

The mamba language model framework thru 2.2.6 is vulnerable to insecure deserialization (CWE-502) when loading pre-trained models from HuggingFace Hub. The MambaLMHeadModel.from_pretrained() method uses torch.load() to load the pytorch_model.bin weight file without enabling the security-restrictive weights_only=True parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by publishing a malicious model repository on HuggingFace Hub. When a victim loads a model from this repository, arbitrary code is executed on the victim's system in the context of the mamba process.

CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0005

Probability of exploitation

0.17%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-502 Deserialization of Untrusted Data

References

Other References

https://github.com/state-spaces/mamba https://www.notion.so/CVE-2026-31239-35d1e1393188810d9baedfbd8363f396

Frequently Asked Questions

What is CVE-2026-31239? +

The mamba language model framework thru 2.2.6 is vulnerable to insecure deserialization (CWE-502) when loading pre-trained models from HuggingFace Hub. The MambaLMHeadModel.from_pretrained() method uses torch.load() to load the pytorch_model.bin weight file without enabling the security-restrictive weights_only=True parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by publishing a malicious model repository on HuggingFace Hub. When a victim loads a model from this repository, arbitrary code is executed on the victim's system in the context of the mamba process. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-31239? +

CVE-2026-31239 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0005, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-31239? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-41486

Ray is an AI compute engine. From version 2.54.0 to before version 2.55.0, Ray Data registers custom Arrow extension types …

CVE-2026-44126

SEPPmail Secure Email Gateway before version 15.0.4 insecurely deserializes untrusted data, which can be reached from the new GINA UI …

CVE-2025-1077

A security vulnerability has been identified in the IBL Software Engineering Visual Weather and derived products (NAMIS, Aero Weather, Satellite …

CVE-2025-0769

PixelYourSite - Your smart PIXEL (TAG) and API Manager 10.1.1.1 was found to be vulnerable. Unvalidated user input is used …

CVE-2025-3425

The IntelliSpace portal application utilizes .NET Remoting for its functionality. The vulnerability arises from the exploitation of port 755 through …

CVE-2025-47292

Cap Collectif is an online decision making platform that integrates several tools. Before commit 812f2a7d271b76deab1175bdaf2be0b8102dd198, the `DebateAlternateArgumentsResolver` deserializes a `Cursor`, …