SimpleEval: Objects (including modules) can leak dangerous modules through to direct access inside the sandbox

CVE-2026-32640 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

If the objects passed in as names to SimpleEval have modules or other disallowed / dangerous objects available as attrs.
Additionally, dangerous functions or modules could be accessed by passing them as callbacks to other safe functions to call.

Examples (found by @ByamB4):

Any module where non-underscore attribute chains reach os or sys:
- os.path, pathlib, shutil, glob (direct .os / .sys attributes)
- statistics (has .sys)
- numpy (has .ctypeslib.os and .f2py.sys)
- urllib.parse (has .warnings.sys)

Patches

The latest version 1.0.5 has this issue fixed.

Workarounds

Don't pass in objects or modules which have direct attributes to potentially dangerous items.
Use a wrapper to wrap the potentially vulnerable items (See the ModuleWrapper in version 1.0.5)

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-13 20:56:26 UTC
Updated
2026-06-08 19:47:09 UTC
GitHub reviewed
2026-03-13 20:56:26 UTC
NVD published
2026-03-16

EPSS Score

Score Percentile
0.05% 16.52%

CVSS Scores

Base score Version Severity Vector
9.8 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
8.7 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

Type Value
GHSA GHSA-44vg-5wv2-h2hg ↗
CVE CVE-2026-32640 ↗

CWEs

CWE id Name
CWE-94 Improper Control of Generation of Code ('Code Injection')
CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes

Credits

  • ByamB4 (finder)
  • danthedeckie (other)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip simpleeval < 1.0.5 1.0.5 —

References

cvelogic Threat Intelligence