CVE-2024-52804: Tornado is a Python web framework and asynchronous networking library

Q: How do I fix CVE-2024-52804?

tornado: upgrade to 6.4.2. Exact commands for each OS are on this page.

Q: Is CVE-2024-52804 being exploited?

CVE-2024-52804 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2024-52804 affect?

CVE-2024-52804 affects tornado. Severity is high (CVSS 7.5). Tornado is a Python web framework and asynchronous networking library. The algorithm used for parsing HTTP cookies in Tornado versions prior to 6.4.2 sometimes has quadratic complexity, leading to excessive CPU consumption when parsing mali

Q: How urgent is CVE-2024-52804?

Priority 47/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2024-52804 is a high-severity flaw (CVSS 7.5) affecting tornado. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Tornado is a Python web framework and asynchronous networking library. The algorithm used for parsing HTTP cookies in Tornado versions prior to 6.4.2 sometimes has quadratic complexity, leading to excessive CPU consumption when parsing maliciously-crafted cookie headers. This parsing occurs in the event loop thread and may block the processing of other requests. Version 6.4.2 fixes the issue.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 36%)
CISA exploited list	No
Weakness	CWE-400, CWE-770
Published	2024-11-22
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: tornadoweb

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-11-22 16:15 UTCPublished CVE record published
2026-06-17 08:07 UTCUpdated Record last modified

tornadoweb tornado UPGRADE

Affected: < 6.4.2

Fixed in: 6.4.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy tornado || rpm -q tornado || tornado --version

2. UPGRADE to 6.4.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tornado

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tornado

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-52804?

tornado: upgrade to 6.4.2. Exact commands for each OS are on this page.

Is CVE-2024-52804 being exploited?

CVE-2024-52804 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-52804 affect?

CVE-2024-52804 affects tornado. Severity is high (CVSS 7.5). Tornado is a Python web framework and asynchronous networking library. The algorithm used for parsing HTTP cookies in Tornado versions prior to 6.4.2 sometimes has quadratic complexity, leading to excessive CPU consumption when parsing mali

How urgent is CVE-2024-52804?

Priority 47/100. High severity; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

Related CVEs

CVE-2025-67725 HIGH 7.5 UPGRADE Tornado is a Python web framework and asynchronous networking library
CVE-2025-67726 HIGH 7.5 UPGRADE Tornado is a Python web framework and asynchronous networking library
CVE-2025-67724 MEDIUM 5.4 UPGRADE Tornado is a Python web framework and asynchronous networking library
CVE-2026-35536 HIGH 7.2 UPGRADE In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite argumen
CVE-2025-47287 HIGH 7.5 UPGRADE MITIGATE Tornado is a Python web framework and asynchronous networking library

References

← Back to latest CVEs