high CVSS 7.8 EPSS 0.44%

CVE-2026-22607·Python vulnerability

Fickling is a Python pickling decompiler and static analyzer. Fickling versions up to and including 0.1.6 do not treat Python's cProfile module as unsafe. Because of this, a malicious pickle that uses cProfile.run() is classified as SUSPICIOUS instead of OVERTLY_MALICIOUS. If a user relies on Fickling's output to decide whether a pickle is safe to deserialize, this misclassification can lead them to execute attacker-controlled code on their system. This affects any workflow or product that uses Fickling as a security gate for pickle deserialization. This issue has been patched in version 0.1.7.

Severity
high
Software
Python
Fixed in
0.1.7
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at 0.44% — higher than 35% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2026-22607 scores 7.8 on CVSS, so a successful attack would be serious — but at 0.44%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

Until: 0.1.7

Fixed in: 0.1.7

How to fix this CVE

Update the Fickling Python package to version 0.1.7 or later to resolve the security classification bypass. The vulnerability allows malicious pickle files using cProfile.run() to evade detection as dangerous code, potentially leading to unauthorized code execution if security checks are bypassed. Ensure your Python environment and any tools relying on Fickling for pickle validation are patched immediately.

sudo dnf update python3-fickling

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'pip show fickling' or 'python3 -c "import fickling; print(fickling.__version__)"' to identify the installed Fickling version
  2. Check if Fickling is used in your codebase by searching for 'import fickling' or 'from fickling' in Python source files
  3. Review pickle deserialization workflows in your application to determine if Fickling is used as a security gate before unpickling untrusted data
  4. After patching, re-run 'pip show fickling' to confirm version 0.1.7 or later is installed, then test with a known malicious pickle using cProfile to verify detection

FAQ

What is CVE-2026-22607?

CVE-2026-22607 is a security bypass vulnerability in Fickling (a Python pickle security analyzer) where malicious pickles invoking cProfile.run() are incorrectly classified as SUSPICIOUS instead of OVERTLY_MALICIOUS, allowing attackers to bypass safety checks and execute arbitrary code.

Is CVE-2026-22607 being actively exploited?

No, CVE-2026-22607 is not currently listed as actively exploited in the CISA KEV catalog, and no public exploit code is available. However, the vulnerability poses a high risk to systems relying on Fickling for security decisions.

What versions of Fickling are affected by CVE-2026-22607?

All versions of Fickling up to and including 0.1.6 are vulnerable. Version 0.1.7 and later contain the fix.

How do I check if my server is vulnerable to CVE-2026-22607?

Run 'pip show fickling' and check the version field. If it shows version 0.1.6 or earlier, your system is vulnerable. You can also run 'python3 -c "import fickling; print(fickling.__version__)"' to verify.

Does Defensia detect CVE-2026-22607?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Fickling is installed on a monitored server, CVE-2026-22607 will appear in your dashboard with remediation steps.

Related Python CVEs

CVE-2026-25632CVSS 10EPyT-Flow is a Python package designed for the easy generation of hydraulic and water quality scenario data of water distribution networks. Prior to 0.16.1, EPyT-Flow’s REST API parses attacker-controlled JSON request bodies using a custom deserializer (my_load_from_json) that supports a type field. When type is present, the deserializer dynamically imports an attacker-specified module/class and instantiates it with attacker-supplied arguments. This allows invoking dangerous classes such as subprocess.Popen, which can lead to OS command execution during JSON parsing. This also affects the loading of JSON files. This vulnerability is fixed in 0.16.1.
CVE-2026-33054CVSS 10Mesop is a Python-based UI framework that allows users to build web applications. Versions 1.2.2 and below contain a Path Traversal vulnerability that allows any user supplying an untrusted state_token through the UI stream payload to arbitrarily target files on the disk under the standard file-based runtime backend. This can result in application denial of service (via crash loops when reading non-msgpack target files as configurations), or arbitrary file manipulation. This vulnerability heavily exposes systems hosted utilizing FileStateSessionBackend. Unauthorized malicious actors could interact with arbitrary payloads overwriting or explicitly removing underlying service resources natively outside the application bounds. This issue has been fixed in version 1.2.3.
CVE-2026-34938CVSS 10PraisonAI is a multi-agent teams system. Prior to version 1.5.90, execute_code() in praisonai-agents runs attacker-controlled Python inside a three-layer sandbox that can be fully bypassed by passing a str subclass with an overridden startswith() method to the _safe_getattr wrapper, achieving arbitrary OS command execution on the host. This issue has been patched in version 1.5.90.
CVE-2026-28505CVSS 10Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to version 2.17.0, the str_eval() function in notification_handler.py implements a sandboxed eval() for notification text templates. The sandbox attempts to restrict callable names by inspecting code.co_names of the compiled code object. However, co_names only contains names from the outer code object. When a lambda expression is used, it creates a nested code object whose attribute accesses are stored in code.co_consts, NOT in code.co_names. The sandbox never inspects nested code objects. This issue has been patched in version 2.17.0.
CVE-2026-25115CVSS 9.9n8n is an open source workflow automation platform. Prior to version 2.4.8, a vulnerability in the Python Code node allows authenticated users to break out of the Python sandbox environment and execute code outside the intended security boundary. This issue has been patched in version 2.4.8.

References

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2026-22607. Free for 1 server.

Get started free