Picklescan Vulnerable to Exfiltration via DNS via linecache and ssl.get_server_certificate

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2025-46417: 0.23% estimated exploitation activity in the next 30 days; percentile 13.68 (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 does not detect malicious pickles that exfiltrate sensitive information via DNS after deserialization. Details picklescan’s blacklist can be bypassed to exfiltrate sensitive information (like file contents, secrets, or credentials) during model deserialization by leveraging ssl.getservercertificate as the callable function in the pickle payload. Since ssl is a standard Python library used for legitimate TLS operations, it is rarely blacklisted by static scanners or runtime monitors. The payload avoids flagged modules and instead uses linecache (also unflagged) to read local files. The exfiltrated data is added to DNS-safe chunks, and embedded as subdomains in a crafted FQDN. When passed to ssl.getservercertificate, the Python runtime performs a DNS resolution to the attacker-controlled domain, leaking the encoded content. The payload executes the following steps: - Reads sensitive local file content using linecache module - Encodes the data for DNS exfiltration -…

Published by the source

7 Apr 2025, 18:52 UTC

Last modified by the source

8 Jul 2026, 07:14 UTC

Source last checked

26 Oct 2026, 13:32 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-93mv-x874-956g

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-93mv-x874-956g

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# Patch Next advisory brief: CVE-2025-46417

Advisory: Picklescan Vulnerable to Exfiltration via DNS via linecache and ssl.get_server_certificate
IDs: CVE-2025-46417, GHSA-93mv-x874-956g
Record: https://patchnext.com/advisories/cve-2025-46417 (revision 3, source checked 26 Oct 2026, 13:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: picklescan 0.0.25. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI picklescan: affected < 0.0.25; fixed in 0.0.25

## 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-93mv-x874-956g (OSV record GHSA-93mv-x874-956g lists affected ranges: PyPI picklescan >=0 <0.0.25 (fixed))
- Verified: https://github.com/advisories/GHSA-93mv-x874-956g (GitHub-reviewed advisory GHSA-93mv-x874-956g lists affected ranges: PyPI picklescan >=0 <0.0.25)

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