Picklescan missing detection when calling pty.spawn

Exploitation

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

CVSS 4.0

8.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Using pty.spawn, which is a built-in python library function to execute arbitrary commands on the host system. Details The attack payload executes in the following steps: First, the attacker craft the payload by calling to pty.spawn function in the reduce method. Then the victim attempts to use picklescan to scan the pickle file for issues and sees this - The victim proceeds to load the pickle file and execute attacker-injected arbitrary code. PoC Impact Who is impacted? Any organization or individual relying on picklescan to detect malicious pickle files inside PyTorch models. What is the impact? Attackers can embed malicious code in pickle file that remains undetected but executes when the pickle file is loaded. Supply Chain Attack: Attackers can distribute infected pickle files across ML models, APIs, or saved Python objects. Collaborators https://github.com/ajohnston9 https://github.com/geo-lit

Published by the source

29 Dec 2025, 15:24 UTC

Last modified by the source

16 Jan 2026, 15:23 UTC

Source last checked

26 Oct 2026, 13:36 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-vqmv-47xg-9wpr

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-vqmv-47xg-9wpr

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# Patch Next advisory brief: GHSA-vqmv-47xg-9wpr

Advisory: Picklescan missing detection when calling pty.spawn
IDs: GHSA-vqmv-47xg-9wpr
Record: https://patchnext.com/advisories/ghsa-vqmv-47xg-9wpr (revision 3, source checked 26 Oct 2026, 13:36 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: picklescan 0.0.33. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI picklescan: affected < 0.0.33; fixed in 0.0.33

## 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://osv.dev/vulnerability/GHSA-vqmv-47xg-9wpr (OSV record GHSA-vqmv-47xg-9wpr lists affected ranges: PyPI picklescan >=0 <0.0.33 (fixed))
- Verified: https://github.com/advisories/GHSA-vqmv-47xg-9wpr (GitHub-reviewed advisory GHSA-vqmv-47xg-9wpr lists affected ranges: PyPI picklescan >=0 <0.0.33)

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