CyberSecBulletin
CVE-2026-7210NVD status: Modified

CPython: Insufficient Entropy

Published Updated By the CyberSecBulletin desk

CVE-2026-7210 is a high-severity insufficient entropy vulnerability in CPython from Python Software Foundation, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 3.10.22, 3.11.16, 3.12.14 as the first without the flaw, so updating CPython to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.67% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update CPython to 3.10.22 or 3.11.16 or 3.12.14 or 3.13.14, whichever matches your release line, or a later version.
  2. Update Python to 3.13.14 or 3.14.6, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Python Software FoundationCPythonbefore 3.10.22; 3.11.0 up to, but not including, 3.11.16; 3.12.0 up to, but not including, 3.12.14; 3.13.0 up to, but not including, 3.13.14; 3.14.0 up to, but not including, 3.14.6; 3.15.0a1 up to, but not including, 3.15.0b23.10.22, 3.11.16, 3.12.14, 3.13.14, 3.14.6, 3.15.0b2
PythonPythonbefore 3.13.14; 3.14.0 up to, but not including, 3.14.6; 3.15.03.13.14, 3.14.6

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.06.3MediumCNA (python.org)
CVSS 3.17.5HighNVD

Official description

`xml.parsers.expat` and `xml.etree.ElementTree` use insufficient entropy for Expat hash-flooding protection, which allows a crafted XML document to trigger hash flooding.\r\n\r\nFully mitigating this vulnerability requires both updating libexpat to 2.8.0 or later and applying this patch.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Insufficient Entropy

The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.

How developers prevent this class of flaw

  • Determine the necessary entropy to adequately provide for randomness and predictability. This can be achieved by increasing the number of bits of objects such as keys and seeds.

More Insufficient Entropy vulnerabilities (CWE-331)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other references

Other vulnerabilities in CPython

All CPython vulnerabilities

Recent Insufficient Entropy vulnerabilities

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