GHSA-j7j6-7hfx-5522 is a high-severity (CVSS 7.5) CWE-444 vulnerability in waitress. A fix is available for waitress — see the affected versions and patch details below.
Duplicate Advisory: Inconsistent Interpretation of HTTP Requests in Waitress
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-j7j6-7hfx-5522 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
waitressReal-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
Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-4ppp-gpcr-7qf6. This link is maintained to preserve external references.
Original Description
Waitress through version 1.3.1 allows request smuggling by sending the Content-Length header twice. Waitress would header fold a double Content-Length header and due to being unable to cast the now comma separated value to an integer would set the Content-Length to 0 internally. If two Content-Length headers are sent in a single request, Waitress would treat the request as having no body, thereby treating the body of the request as a new request in HTTP pipelining. This issue is fixed in Waitress 1.4.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | waitress | all versions | 1.4.0pip install --upgrade 'waitress==1.4.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for waitress, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update waitress to 1.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j7j6-7hfx-5522 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-j7j6-7hfx-5522 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-j7j6-7hfx-5522. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-j7j6-7hfx-5522 in your dependencies?
O3 Security finds GHSA-j7j6-7hfx-5522 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.