CVE-2025-13837

When loading a plist file, the plistlib module reads data in size specified by the file itself, meaning a malicious file can cause OOM and DoS issues

What this means for your business

It affects Python. It matters if your company, or a supplier that handles your data, runs it.
An attacker can use it only with access to the machine itself, without a login, but only after tricking someone into an action such as opening a file or a link.
FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 13% of all known flaws.

What to do

1Check whether your company or your suppliers run Python, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS: 5.5 (v3.1)
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS v4: 2.1
Weakness: CWE-400
Assigned by: cna@python.org

Dates

Published: 2025-12-01
Last modified: 2026-09-03
Sources: NVD

Affected products

Python Python- 3.13.10, 3.14.0 - 3.14.1, 3.15.0

As listed in the NVD configuration data. Not a statement about your estate.