Deserialization in Picklescan
CVE-2025-71343
picklescan before 0.0.30 fails to detect malicious pickle files that exploit lib2to3.pgen2.pgen.ParserGenerator.make_label function in the reduce method. Attackers can craft malicious pickle files with embedded code that evades detection but executes arbitrary commands when pickle.load() is called.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (29.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: -0.001
Affected products
- Picklescan — versions 0, 0.0.30
Weakness classification (CWE)
References
- github.com/mmaitre314/picklescan/security/advisories/GHSA-p9w7-82w4-7q8m (vendor-advisory)
- www.vulncheck.com/advisories/picklescan-arbitrary-code-execution-via-lib2to3-pg… (third-party-advisory)
Frequently asked questions
- What is CVE-2025-71343?
- CVE-2025-71343 is a high-severity vulnerability in Picklescan, classified under Deserialization of Untrusted Data. CVSS score: 8.1/10. Published 2026-07-04.
- How severe is CVE-2025-71343?
- High severity. CVSS v3 base score is 8.1 out of 10.