PickleScan has multiple stdlib modules with direct RCE not in blocklist

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-2026-56315: 1.15% estimated exploitation activity in the next 30 days; percentile 66.83 (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 (latest) does not block at least 7 Python standard library modules that provide direct arbitrary command execution or code evaluation. A malicious pickle file importing these modules is reported as having 0 issues (CLEAN scan). This enables remote code execution that bypasses picklescan entirely. Severity Critical (CVSS 9.8) — Direct RCE with zero scanner detection. Affects all deployments relying on picklescan, including HuggingFace Hub. Affected Versions - picklescan <= 1.0.3 (all versions including latest) Details Unblocked RCE Modules | Module | Function | RCE Mechanism | picklescan Result | |--------|----------|--------------|-------------------| | uuid | getcommandstdout(cmd, args) | subprocess.Popen((cmd,) + args) | CLEAN | | osxsupport | readoutput(cmdstring) | os.system() via temp file | CLEAN | | osxsupport | findbuildtool(toolname) | Command injection via %s | CLEAN | | aixsupport | readcmdoutput(cmdstring) | os.system() | CLEAN | | pyrepl.pager |…

Published by the source

3 Mar 2026, 20:05 UTC

Last modified by the source

1 Oct 2026, 17:56 UTC

Source last checked

26 Oct 2026, 13:54 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-g38g-8gr9-h9xp

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-g38g-8gr9-h9xp

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-g38g-8gr9-h9xp

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# Patch Next advisory brief: CVE-2026-56315

Advisory: PickleScan has multiple stdlib modules with direct RCE not in blocklist
IDs: CVE-2026-56315, GHSA-g38g-8gr9-h9xp
Record: https://patchnext.com/advisories/cve-2026-56315 (revision 3, source checked 26 Oct 2026, 13:54 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-g38g-8gr9-h9xp (GitHub-reviewed advisory GHSA-g38g-8gr9-h9xp lists affected ranges: PyPI picklescan >=0 <1.0.4)
- Verified: https://osv.dev/vulnerability/GHSA-g38g-8gr9-h9xp (OSV record GHSA-g38g-8gr9-h9xp lists affected ranges: PyPI picklescan >=0 <1.0.4 (fixed))

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