Vulnerability · Published Jul 4, 2026 · Assigned by VulnCheck
CVE-2025-71343picklescan - Arbitrary Code Execution via lib2to3.pgen2.pgen.ParserGenerator.make_label Detection Bypass
High 8.1
In plain English
A high-severity unsafe deserialization in picklescan from picklescan. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.4%top 67.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | picklescan | 0.0.30 | GHSA-p9w7-82w4-7q8m |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| picklescan | picklescan | 0 – before 0.0.30 |
Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N