PickleScan's profile.run blocklist mismatch allows exec() bypass

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-53873: 0.46% estimated exploitation activity in the next 30 days; percentile 39.90 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary picklescan v1.0.3 blocks profile.Profile.run and profile.Profile.runctx but does NOT block the module-level profile.run() function. A malicious pickle calling profile.run(statement) achieves arbitrary code execution via exec() while picklescan reports 0 issues. This is because the blocklist entry "Profile.run" does not match the pickle global name "run". Severity High — Direct code execution via exec() with zero scanner detection. Affected Versions - picklescan v1.0.3 (latest — the profile entries were added in recent versions) - Earlier versions also affected (profile not blocked at all) Details Root Cause In scanner.py line 199, the blocklist entry for profile is: When a pickle file imports profile.run (the module-level function), picklescan's opcode parser extracts: - module = "profile" - name = "run" The blocklist check at line 414 is: This checks: is "run" in {"Profile.run", "Profile.runctx"}? Answer: NO. "run" != "Profile.run". The string comparison is exact — there is…

Published by the source

3 Mar 2026, 20:03 UTC

Last modified by the source

29 Jun 2026, 12:26 UTC

Source last checked

26 Oct 2026, 13:45 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-7wx9-6375-f5wh

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-7wx9-6375-f5wh

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-7wx9-6375-f5wh

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-53873

Advisory: PickleScan's profile.run blocklist mismatch allows exec() bypass
IDs: CVE-2026-53873, GHSA-7wx9-6375-f5wh
Record: https://patchnext.com/advisories/cve-2026-53873 (revision 3, source checked 26 Oct 2026, 13:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: picklescan 1.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI picklescan: affected < 1.0.4; fixed in 1.0.4

## Suggested inspection (read-only)
- `python -m pip show picklescan`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on picklescan.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7wx9-6375-f5wh (GitHub-reviewed advisory GHSA-7wx9-6375-f5wh lists affected ranges: PyPI picklescan >=0 <1.0.4)
- Verified: https://osv.dev/vulnerability/GHSA-7wx9-6375-f5wh (OSV record GHSA-7wx9-6375-f5wh lists affected ranges: PyPI picklescan >=0 <1.0.4 (fixed))

Commands are suggestions: review each one before running it.