CVE-2026-22612 Fickling vulnerable to detection bypass due to "builtins" blindness

High 8.9 Published Updated

Fickling fails to detect malicious builtins in pickled data, allowing attackers to bypass security checks during static analysis.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-22612?

CVE-2026-22612 is a high-severity unsafe deserialization vulnerability in trailofbits fickling, published on 10 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Fickling is a Python pickling decompiler and static analyzer. Prior to version 0.1.7, Fickling is vulnerable to detection bypass due to "builtins" blindness. This issue has been patched in version 0.1.7.

Weakness: CWE-502

Which versions are affected by CVE-2026-22612?

3 open source packages ship an affected version, including fickling. It affects 1 product.

PackageAffectedFixed in
fickling PyPIAll versions0.1.7
fickling PyPIAll versions0.1.7
fickling PyPIAll versions0.1.7

Products include Trailofbits Fickling.

How do I fix CVE-2026-22612?

Upgrade fickling to 0.1.7 or later.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-22612 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22612 exists.

Sources

Also known as GHSA-h4rm-mm56-xf63, PYSEC-2026-1370.

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