Pylint: Arbitrary code execution via pickle deserialization of the stats cache in PYLINT_HOME

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-114608: 0.11% estimated exploitation activity in the next 30 days; percentile 1.55 (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.

Impact Since 2006 / pylint 0.15.2, pylint caches its stats as pickles in `PYLINT_HOME` and reload them on the next run with `pickle.load`. Someone without access to the configuration or linted code, but with access to the cache directory (predictable `PYLINT_HOME` on a multi-user host) can write a crafted pickle that will runs arbitrary code when pylint access its stat cache.

Patches From pylint 4.0.9, the result cache is now stored as JSON instead of pickle, preventing code-execution.

Workarounds Until upgrading do not point `PYLINT_HOME` to an untrusted, shared, or group-writable directory. The default value, `~/.cache/pylint`, is writable only by the user running pylint.

Credits - Reported privately via Tidelift coordinated disclosure (Dan Lenz).

Published by the source

27 Oct 2026, 14:46 UTC

Last modified by the source

27 Oct 2026, 15:00 UTC

Source last checked

28 Oct 2026, 06:20 UTC

1. Revision 2 · amended · 28 Oct 2026

   Amended from osv record GHSA-22qq-2fwx-7p67

2. Revision 1 · created · 27 Oct 2026

   Published from ghsa record GHSA-22qq-2fwx-7p67

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# Patch Next advisory brief: CVE-2026-114608

Advisory: Pylint: Arbitrary code execution via pickle deserialization of the stats cache in PYLINT_HOME
IDs: CVE-2026-114608, GHSA-22qq-2fwx-7p67
Record: https://patchnext.com/advisories/cve-2026-114608 (revision 2, source checked 28 Oct 2026, 06:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: pylint 4.0.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI pylint: affected < 4.0.9; fixed in 4.0.9

## Suggested inspection (read-only)
- `python -m pip show pylint`: 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 pylint.
- 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-22qq-2fwx-7p67 (OSV record GHSA-22qq-2fwx-7p67 lists affected ranges: PyPI pylint >=0 <4.0.9 (fixed))
- Verified: https://github.com/advisories/GHSA-22qq-2fwx-7p67 (GitHub-reviewed advisory GHSA-22qq-2fwx-7p67 lists affected ranges: PyPI pylint >=0 <4.0.9)

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