Vulnerability · Published Jul 4, 2026 · Assigned by VulnCheck
CVE-2025-71359picklescan - Unsafe Deserialization via lib2to3.pgen2.grammar.Grammar.loads
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 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.6%top 50.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
picklescan before 0.0.29 fails to detect malicious pickle payloads that utilize lib2to3.pgen2.grammar.Grammar.loads in the reduce method, allowing remote code execution. Attackers can craft pickle files embedding dangerous code that evades picklescan detection and executes during pickle.load() deserialization.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | picklescan | 0.0.29 | GHSA-f54q-57x4-jg88 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| picklescan | picklescan | 0 – before 0.0.29 |
Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
References
- GitHub Security Advisory (GHSA-f54q-57x4-jg88) vendor-advisory
- VulnCheck Advisory: picklescan - Unsafe Deserialization via lib2to3.pgen2.grammar.Grammar.loads third-party-advisory