CVE-2026-14534
Description
A flaw was found in the fickling library, which is designed to safely handle Python pickle data. The library's security checks in versions up to and including 0.1.10 fail to properly identify and block certain dangerous Python standard library modules during deserialization. This oversight allows a remote attacker to craft a malicious data payload that, when processed, can execute arbitrary code on the system, potentially leading to full system compromise.
Statement
A flaw was found in Trail of Bits fickling versions through 0.1.10, where the UNSAFE_IMPORTS denylist is missing the Python standard library modules _posixsubprocess, site, and atexit. This allows a crafted pickle payload to invoke dangerous functions such as _posixsubprocess.fork_exec (arbitrary binary execution), site.execsitecustomize (arbitrary code execution), and atexit._run_exitfuncs (triggering all registered exit handlers) while fickling's check_safety() returns LIKELY_SAFE.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | N/A | 8.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Attackers may be able to find other malicious inputs that were not expected by the developer, allowing them to bypass the intended protection mechanism.
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