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Not in CISA KEV
HIGH severity

CVE-2024-49769 — waitress

HIGHFix: Pylons/waitress@1ae4e89

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

Also known asGHSA-3f84-rpwh-47g6PYSEC-2024-211
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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

via FIRST.org ↗
1.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs72th percentile — riskier than 72% of all scored CVEsHighest risk
0.68%1.13%1.58%2.02%1.2%1.4%May 26Sep 26Nov 26

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐍waitress

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

Impact

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.

Patches

Waitress 3.0.1 contains fixes that remove the race condition.

Workarounds

No work-around.

References

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIwaitressall versions3.0.1pip install --upgrade 'waitress==3.0.1'

Affected Products

1 product · 1 configurations
Application
waitressagendaless
< 3.0.1
range

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. 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.

  3. 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 HatImportant
Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for CVE-2024-49769 (CC BY 4.0)
ProductFixed inAdvisory
Ironic content for Red Hat OpenShift Container Platform 4.12python-waitress-0:3.0.1-1.el9RHSA-2024:10535
Ironic content for Red Hat OpenShift Container Platform 4.13python-waitress-0:3.0.1-1.el9RHSA-2024:10815
Red Hat OpenShift Container Platform 4.14python-waitress-0:3.0.1-1.el9RHSA-2024:9623
Red Hat OpenShift Container Platform 4.15python-waitress-0:3.0.1-1.el9RHSA-2024:10145
Red Hat OpenShift Container Platform 4.16python-waitress-0:3.0.1-1.el9RHSA-2024:9618
Red Hat OpenShift Container Platform 4.17python-waitress-0:3.0.1-1.el9RHSA-2024:9613
Red Hat OpenStack Platform 16.2python-waitress-0:2.0.0-4.el8ostRHSA-2025:0201
Red Hat OpenStack Platform 17.1 for RHEL 8python-waitress-0:2.0.0-4.el8ostRHSA-2025:1192

Frequently Asked Questions

### Impact 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. ### Patches Waitress 3.0.1 contains fixes that remove the race condition. ### Workarounds No work-around. ### References -
O3 Security · Impact-Aware SCA

Is CVE-2024-49769 in your dependencies?

Find it across PyPI, including transitive dependencies.

CVE-2024-49769: waitress — Fixed in 3.0.1