Security Digest · Vulnerability record
CVE-2025-10156: Picklescan: ZIP archive scan bypass is possible through non-exhaustive Cyclic Redundancy Check
An Improper Handling of Exceptional Conditions vulnerability in the ZIP archive scanning component of mmaitre314 picklescan allows a remote attacker to bypass security scans.
CVSS 9.3 Critical EPSS 1.5% · p74
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 1.5%, percentile 74: FIRST’s model estimates a 1.5% chance of exploitation activity in the next 30 days, higher than 74% 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
An Improper Handling of Exceptional Conditions vulnerability in the ZIP archive scanning component of mmaitre314 picklescan allows a remote attacker to bypass security scans. This is achieved by crafting a ZIP archive containing a file with a bad Cyclic Redundancy Check (CRC), which causes the scanner to halt and fail to analyze the contents for malicious pickle files. When the file incorrectly considered safe is loaded, it can lead to the execution of malicious code.
From the GitHub advisory
Summary Picklescan's ability to scan ZIP archives for malicious pickle files is compromised when the archive contains a file with a bad Cyclic Redundancy Check (CRC). Instead of attempting to scan the files within the archive, whatever the CRC is, Picklescan fails in error and returns no results. This allows attackers to potentially hide malicious pickle payloads within ZIP archives that PyTorch might still be able to load (as PyTorch often disables CRC checks).
Details Picklescan likely utilizes Python's built-in zipfile module to handle ZIP archives. When zipfile encounters a file within an archive that has a mismatch between the declared CRC and the calculated CRC, it can raise an exception (e.g., BadZipFile or a related error). It appears that Picklescan does not try to scan the files whatever the CRC is. This behavior contrasts with PyTorch's model loading capabilities, which in many cases might bypass CRC checks for ZIP archives - whatever the configuration is. This discrepancy creates a blind spot where a malicious model packaged in a ZIP with a bad CRC could be loaded by PyTorch while being completely missed by Picklescan.
PoC
1. Download an existing Pytorch model with a bad CRC
wget -O pytorchmodel.bin
Weakness type: CWE-755, CWE-693.
Product: picklescan (PyPI) · Assigned by: JFROG · Published: 2025-09-17
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| PyPI | picklescan | <= 0.0.30 | 0.0.31 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| mmaitre314 | picklescan | <= 0.0.30 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| JFROG | 4.0 | 9.3 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| GitHub | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
- 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): 1.48% probability of exploitation activity in the next 30 days; percentile 74.
Timeline
- — GitHub-reviewed advisory GHSA-mjqp-26hc-grxg published (critical)
- — CVE record last updated
- — 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
- github.com github.com
Vulnerability records
- GitHub Advisory GHSA-mjqp-26hc-grxg github.com
- CVE.org record CVE-2025-10156 cve.org
- NVD entry CVE-2025-10156 nvd.nist.gov
Other references from the CVE record and advisory
- Proof of Concept (Archive with Bad CRC) huggingface.co
- Example of Failing Scan on Hugging Face huggingface.co
- Vulnerable Code Snippet github.com
- github.com github.com
- github.com github.com