CVE-2025-67724: Tornado is a Python web framework and asynchronous networking library

Q: How do I fix CVE-2025-67724?

tornado: upgrade to 6.5.3. Exact commands for each OS are on this page.

Q: Is CVE-2025-67724 being exploited?

CVE-2025-67724 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-2025-67724 affect?

CVE-2025-67724 affects tornado. Severity is medium (CVSS 5.4). Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error p

Q: How urgent is CVE-2025-67724?

Priority 23/100. No elevated risk signals yet.

Routine

MEDIUM 5.4UPGRADE

CVE-2025-67724 is a medium-severity flaw (CVSS 5.4) 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. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is desig

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 85%)
CISA exploited list	No
Weakness	CWE-79, CWE-644
Published	2025-12-12
Last modified	2026-10-07

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

Last updated 2026-10-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-12-12 06:15 UTCPublished CVE record published
2026-10-07 20:10 UTCUpdated Record last modified

tornadoweb tornado UPGRADE

Affected: < 6.5.3

Fixed in: 6.5.3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 6.5.3 (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-2025-67724?

tornado: upgrade to 6.5.3. Exact commands for each OS are on this page.

Is CVE-2025-67724 being exploited?

CVE-2025-67724 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-2025-67724 affect?

CVE-2025-67724 affects tornado. Severity is medium (CVSS 5.4). Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error p

How urgent is CVE-2025-67724?

Priority 23/100. No elevated risk signals yet.

Software pages

Python vulnerabilities

Related CVEs

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CVE-2025-47287 HIGH 7.5 UPGRADE MITIGATE Tornado is a Python web framework and asynchronous networking library
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References

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