CVE-2026-102734 (CVSS 5.5)

Description

asteval is a Python expression evaluator designed for restricted execution. Prior to 1.0.9, in asteval/astutils.py, the default Interpreter with numpy enabled exposes a ctypes type and permits from_address memory access. safe_getattr blocks the ctypes module but not reachable ctypes type objects, while attribute assignments use unfiltered setattr instead of safe_setattr. An attacker-controlled expression can derive an address with id, read memory through from_address, and write through an attribute assignment. The expression can read or corrupt arbitrary process memory, escape the intended sandbox, execute code, disclose secrets, or crash the host process. This issue is fixed in version 1.0.9.

Is your site exposed to CVE-2026-102734?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.5

MEDIUM

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

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.02%

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-693 CWE-693

CWE-749 CWE-749

CWE-913 CWE-913

References

Other References

https://github.com/lmfit/asteval/commit/a3e56e7f8ed567a4817684d94213b290359077b4 https://github.com/lmfit/asteval/pull/153 https://github.com/lmfit/asteval/releases/tag/1.0.9 https://github.com/lmfit/asteval/security/advisories/GHSA-9w56-46f6-3qhx

Frequently Asked Questions

What is CVE-2026-102734? +

asteval is a Python expression evaluator designed for restricted execution. Prior to 1.0.9, in asteval/astutils.py, the default Interpreter with numpy enabled exposes a ctypes type and permits from_address memory access. safe_getattr blocks the ctypes module but not reachable ctypes type objects, while attribute assignments use unfiltered setattr instead of safe_setattr. An attacker-controlled expression can derive an address with id, read memory through from_address, and write through an attribute assignment. The expression can read or corrupt arbitrary process memory, escape the intended sandbox, execute code, disclose secrets, or crash the host process. This issue is fixed in version 1.0.9. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-102734? +

CVE-2026-102734 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-102734? +

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-2026-48033

Hulumi is an open-source toolkit that ships secure-by-default cloud and platform infrastructure components for Pulumi. Prior to version 1.4.0, policy …

CVE-2026-0278

Multiple protection mechanism failures in the Prisma Access Agent Data Loss Prevention (DLP) component for Windows allow a local user …

CVE-2025-3114

Code Execution via Malicious Files: Attackers can create specially crafted files with embedded code that may execute without adequate security …

CVE-2024-51481

Nix is a package manager for Linux and other Unix systems. On macOS, built-in builders (such as `builtin:fetchurl`, exposed to …

CVE-2025-65100

Isar is an integration system for automated root filesystem generation. In versions 0.11-rc1 and 0.11, defining ISAR_APT_SNAPSHOT_DATE alone does not …

CVE-2025-29864

Protection Mechanism Failure vulnerability in ESTsoft ALZip on Windows allows SmartScreen bypass.This issue affects ALZip: from 12.01 before 12.29.

CVE-2026-102734