CVE-2024-0397Network attack vector

Memory race via unlocked certificate-store reads

Published Jun 17, 2024 · Updated Nov 3, 2025

Race condition in affected CPython releases allows attackers to trigger unsafe memory access during concurrent certificate-store operations. The ssl.SSLContext cert_store_stats() and get_ca_certs() methods read an X509_STORE object list without the lock needed while OpenSSL mutates or reorders that shared list. Reaching the flaw requires a shared SSLContext, concurrent certificate-store inspection, and certificate loading such as a TLS handshake with a certificate directory; published material does not specify the resulting failure mode.

CVSS severity7.4
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Race condition in affected CPython releases allows attackers to trigger unsafe memory access during concurrent certificate-store operations. The ssl.SSLContext cert_store_stats() and get_ca_certs() methods read an X509_STORE object list without the lock needed while OpenSSL mutates or reorders that shared list. Reaching the flaw requires a shared SSLContext, concurrent certificate-store inspection, and certificate loading such as a TLS handshake with a certificate directory; published material does not specify the resulting failure mode.

The record

CVE
CVE-2024-0397
Published
Jun 17, 2024
Updated
Nov 3, 2025
Vendor
Python Software Foundation
Product
CPython
Classifications
CWE-362
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 17, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.8.20
  2. Affected versionversion=3.10.0 <3.10.14
  3. Affected versionversion=3.11.0 <3.11.9
  4. Affected versionversion=3.12.0 <3.12.3
  5. Affected versionversion=3.13.0a1 <3.13.0a5
  6. Affected versionversion=3.9.0 <3.9.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Python Software Foundation · CPythonversion=0 <3.8.20; version=3.10.0 <3.10.14; version=3.11.0 <3.11.9; version=3.12.0 <3.12.3; version=3.13.0a1 <3.13.0a5; version=3.9.0 <3.9.20

Published CVSS scores

7.4CISACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo