How severe is GHSA-qppv-j76h-2rpx?

No CVSS score has been assigned to GHSA-qppv-j76h-2rpx yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-qppv-j76h-2rpx?

GHSA-qppv-j76h-2rpx affects the following packages: tornado (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-qppv-j76h-2rpx?

Update tornado to 6.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qppv-j76h-2rpx is resolved across your whole dependency graph.

How do I detect GHSA-qppv-j76h-2rpx in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tornado, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-qppv-j76h-2rpx if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-qppv-j76h-2rpx actively exploited in the wild?

No public exploit code has been indexed for GHSA-qppv-j76h-2rpx yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-qppv-j76h-2rpx?

GHSA-qppv-j76h-2rpx has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 32th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-qppv-j76h-2rpx?

GHSA-qppv-j76h-2rpx is classified as CWE-444 (CWE-444). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-qppv-j76h-2rpx published, and has it been updated?

GHSA-qppv-j76h-2rpx was published on August 14, 2023 and was last updated on September 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

Tornado vulnerable to HTTP request smuggling via improper parsing of `Content-Length` fields and chunk lengthsGHSA-qppv-j76h-2rpx

Fix: tornadoweb/tornado@b7a5dd2

GHSA-qppv-j76h-2rpx is a CWE-444 vulnerability in tornado. A fix is available for tornado — see the affected versions and patch details below.

Also known asCVE-2023-54397

Published

Aug 14, 2023

Updated

Sep 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-qppv-j76h-2rpx.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs32th percentile — riskier than 32% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍tornado

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Tornado interprets -, +, and _ in chunk length and Content-Length values, which are not allowed by the HTTP RFCs. This can result in request smuggling when Tornado is deployed behind certain proxies that interpret those non-standard characters differently. This is known to apply to older versions of haproxy, although the current release is not affected.

Details

Tornado uses the int constructor to parse the values of Content-Length headers and chunk lengths in the following locations:

`tornado/http1connection.py:445`

            self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`

                content_length = int(headers["Content-Length"])  # type: Optional[int]

`tornado/http1connection.py:671`

            chunk_len = int(chunk_len_str.strip(), 16)

Because int("0_0") == int("+0") == int("-0") == int("0"), using the int constructor to parse and validate strings that should contain only ASCII digits is not a good strategy.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`tornado`	all versions	6.3.3`pip install --upgrade 'tornado==6.3.3'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tornado, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tornado to 6.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qppv-j76h-2rpx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatCritical

A vulnerability was found in Tornado's HTTP header parsing logic. When deployed behind a front-end reverse proxy or load balancer, Tornado improperly accepts non-standard characters in Content-Length headers instead of rejecting the malformed request. An unauthenticated remote attacker can exploit this parsing…

Workaround published by Red Hat

Configure upstream reverse proxies or load balancers to strictly normalize or sanitize HTTP headers and reject malformed Content-Length headers before requests reach the Tornado application layer.

Source: Red Hat security advisory for GHSA-qppv-j76h-2rpx (CC BY 4.0)

Frequently Asked Questions

## Summary Tornado interprets `-`, `+`, and `_` in chunk length and `Content-Length` values, which are not allowed by the HTTP RFCs. This can result in request smuggling when Tornado is deployed behind certain proxies that interpret those non-standard characters differently. This is known to apply to older versions of haproxy, although the current release is not affected. ## Details Tornado uses the `int` constructor to parse the values of `Content-Length` headers and chunk lengths in the following locations: ### `tornado/http1connection.py:445` ```python3 self._expected_content_r

O3 Security · Impact-Aware SCA

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