---
title: "CVE-2026-3490: PickleScan's pkgutil.resolve_name has a universal blocklist bypass"
url: https://erroneo.us/security/cve/CVE-2026-3490/
description: "CVE-2026-3490 (picklescan (PyPI)): picklescan before 1.0.4 fails to block pkgutil.resolvename, allowing attackers to bypass the entire blocklist by…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-17
date_modified: 2026-06-18
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-3490"
kev: false
cvss: 10
epss: 0.00909
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-3490: PickleScan's pkgutil.resolve_name has a universal blocklist bypass

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.9% , percentile 60: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 60% 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) < 1.0.4, fixed in 1.0.4 . Check your lockfile, including transitive dependencies.

## What it is

picklescan before 1.0.4 fails to block pkgutil.resolvename, allowing attackers to bypass the entire blocklist by resolving any dangerous function through indirect REDUCE calls. Remote attackers can invoke any blocked function such as os.system, builtins.exec, or subprocess.call to achieve remote code execution.

## Affected packages

- PyPI `picklescan` < 1.0.4 → fixed: 1.0.4

## Affected products (CVE record)

- picklescan picklescan: < 1.0.4

## Severity

- VulnCheck CVSS 4.0: 10 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`
- VulnCheck CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 10.0 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.91% probability of exploitation activity in the next 30 days; percentile 60.

## Sources

- [GHSA Advisory GHSA-vvpj-8cmc-gx39](https://github.com/mmaitre314/picklescan/security/advisories/GHSA-vvpj-8cmc-gx39)
- [GitHub Advisory GHSA-vvpj-8cmc-gx39](https://github.com/advisories/GHSA-vvpj-8cmc-gx39)
- [CVE.org record CVE-2026-3490](https://www.cve.org/CVERecord?id=CVE-2026-3490)
- [NVD entry CVE-2026-3490](https://nvd.nist.gov/vuln/detail/CVE-2026-3490)
- [VulnCheck Advisory: picklescan - Universal Blocklist Bypass via pkgutil.resolve_name](https://www.vulncheck.com/advisories/picklescan-universal-blocklist-bypass-via-pkgutil-resolve-name)

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Source page: https://erroneo.us/security/cve/CVE-2026-3490/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt