CVE-2024-49769 is a high-severity (CVSS 7.5) CWE-772 vulnerability in waitress. A fix is available for waitress — see the affected versions and patch details below.
Waitress has a denial of service leading to high CPU usage/resource exhaustion
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 CVE-2024-49769.
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
CVE-2024-49769 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 377,333 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
Waitress is a Web Server Gateway Interface server for Python 2 and 3. When a remote client closes the connection before waitress has had the opportunity to call getpeername() waitress won't correctly clean up the connection leading to the main thread attempting to write to a socket that no longer exists, but not removing it from the list of sockets to attempt to process. This leads to a busy-loop calling the write function. A remote attacker could run waitress out of available sockets with very little resources required. Waitress 3.0.1 contains fixes that remove the race condition.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | waitress | all versions | 3.0.1pip install --upgrade 'waitress==3.0.1' |
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 3.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-49769 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 CVE-2024-49769 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-49769. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
| Product | Fixed in | Advisory |
|---|---|---|
| Ironic content for Red Hat OpenShift Container Platform 4.12 | python-waitress-0:3.0.1-1.el9 | RHSA-2024:10535 |
| Ironic content for Red Hat OpenShift Container Platform 4.13 | python-waitress-0:3.0.1-1.el9 | RHSA-2024:10815 |
| Red Hat OpenShift Container Platform 4.14 | python-waitress-0:3.0.1-1.el9 | RHSA-2024:9623 |
| Red Hat OpenShift Container Platform 4.15 | python-waitress-0:3.0.1-1.el9 | RHSA-2024:10145 |
| Red Hat OpenShift Container Platform 4.16 | python-waitress-0:3.0.1-1.el9 | RHSA-2024:9618 |
| Red Hat OpenShift Container Platform 4.17 | python-waitress-0:3.0.1-1.el9 | RHSA-2024:9613 |
| Red Hat OpenStack Platform 16.2 | python-waitress-0:2.0.0-4.el8ost | RHSA-2025:0201 |
| Red Hat OpenStack Platform 17.1 for RHEL 8 | python-waitress-0:2.0.0-4.el8ost | RHSA-2025:1192 |
Frequently Asked Questions
Is CVE-2024-49769 in your dependencies?
O3 Security finds CVE-2024-49769 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.