CVE-2025-10157: Picklescan is Vulnerable to Unsafe Globals Check Bypass through Subclass Imports

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.8%, percentile 56: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 56% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes picklescan (PyPI) <= 0.0.30, fixed in 0.0.31. Check your lockfile, including transitive dependencies.

What it is

A Protection Mechanism Failure vulnerability in mmaitre314 picklescan versions up to and including 0.0.30 allows a remote attacker to bypass the unsafe globals check. This is possible because the scanner performs an exact match for module names, allowing malicious payloads to be loaded via submodules of dangerous packages (e.g., 'asyncio.unixevents' instead of 'asyncio'). When the incorrectly considered safe file is loaded after scan, it can lead to the execution of malicious code.

From the GitHub advisory

Summary The vulnerability allows malicious actors to bypass PickleScan's unsafe globals check, leading to potential arbitrary code execution. The issue stems from PickleScan's strict check for full module names against its list of unsafe globals. By using subclasses of dangerous imports instead of the exact module names, attackers can circumvent the check and inject malicious payloads.

PoC 1. Download a model that uses the asyncio package:

2. Check with PickleScan: picklescan -p asyncioasynciounixeventsUnixSubprocessTransportstart.pkl -g

Expected Result:

PickleScan should identify all asyncio import as dangerous and flag the pickle file as malicious as asyncio is in unsafeglobals dictionary.

Weakness type: CWE-693.

Product: picklescan (PyPI) · Assigned by: JFROG · Published: 2025-09-17

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 0.79% probability of exploitation activity in the next 30 days; percentile 56.

Timeline

• 2025-09-10 — GitHub-reviewed advisory GHSA-f7qq-56ww-84cr published (critical)
• 2025-09-17 — CVE record last updated
• 2025-09-17 — CVE record published by JFROG

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. GitHub Security Advisory github.com

Vulnerability records

1. GitHub Advisory GHSA-f7qq-56ww-84cr github.com
2. CVE.org record CVE-2025-10157 cve.org
3. NVD entry CVE-2025-10157 nvd.nist.gov

Other references from the CVE record and advisory

1. Proof of Concept (Malicious Pickle) huggingface.co
2. Vulnerable Code github.com
3. github.com github.com
4. github.com github.com
5. github.com github.com

Critical PyPI advisories · Today’s Security Digest