CVE-2026-14534

Trail of Bits fickling versions up to and including 0.1.10 do not include the Python standard library modules _posixsubprocess, site, and atexit in the UNSAFE_IMPORTS denylist (fickle.py). Because these modules are absent from the denylist, fickling's check_safety() function returns LIKELY_SAFE with zero findings for pickle payloads that invoke dangerous functions including _posixsubprocess.fork_exec (C-level process spawner capable of executing arbitrary binaries), site.execsitecustomize (executes arbitrary site customization code), and atexit._run_exitfuncs (triggers all registered exit handler callbacks). The fickling.load() API chains check_safety() into pickle.loads() as an explicit security gate; a LIKELY_SAFE verdict causes the payload to be deserialized and executed. This shares the same root cause as CVE-2026-22607 (cProfile), CVE-2025-67748 (pty), and CVE-2025-67747 (marshal/types). OvertlyBadEvals does not flag these modules because they are standard library imports. UnsafeImports does not flag them because they are not in the denylist. The UnusedVariables heuristic is defeated by the SETITEMS opcode pattern.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/trailofbits/fickling/commit/e8408615b63adf034f891f653692ab9b51f0f5af	Patch
https://github.com/trailofbits/fickling/pull/272	Issue Tracking Patch
https://github.com/trailofbits/fickling/releases/tag/v0.1.11	Release Notes
https://github.com/trailofbits/fickling/security/advisories/GHSA-m6fh-58r7-x697	Exploit Vendor Advisory
https://github.com/trailofbits/fickling/security/advisories/GHSA-m6fh-58r7-x697	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:trailofbits:fickling:*:*:*:*:*:python:*:*

History

No history.

Information

Published : 2026-07-04 14:16

Updated : 2026-07-10 15:10

NVD link : CVE-2026-14534

Mitre link : CVE-2026-14534

CVE.ORG link : CVE-2026-14534

JSON object : View

Products Affected

trailofbits

fickling

CWE

CWE-184

Incomplete List of Disallowed Inputs

CWE-502

Deserialization of Untrusted Data

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