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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Pylons | waitress | < 3.0.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | waitress | 3.0.1-1 | — |
| Debian 13 | waitress | 3.0.1-1 | — |
| Debian 12 | waitress | 2.1.2-2+deb12u1 | — |
| Debian 11 | waitress | 1.4.4-1.1+deb11u2 | DLA-3955-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | waitress | 1.4.4-1.1ubuntu1.1 | USN-7115-1 |
| Ubuntu 20.04 LTS | waitress | 1.4.1-1ubuntu0.2 | USN-7115-1 |
| Ubuntu 18.04 LTS | waitress | No fix yet | — |
| Ubuntu 16.04 LTS | waitress | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | waitress | 2.1.2-2ubuntu0.1~esm1 | USN-7115-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Openshift Ironic 4 | python-waitress +1 | 3.0.1-1.el9 | RHSA-2024:10815, RHSA-2024:10535, RHSA-2024:10145 |
| Red Hat OpenStack 17 | python-waitress +1 | 2.0.0-4.el8ost | RHSA-2025:1192, RHSA-2025:1191 |
| Red Hat OpenStack 16 | python-waitress +1 | 2.0.0-4.el8ost | RHSA-2025:0201 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLES 15 SP5 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLES 15 SP4 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1, SUSE-SU-2024:3876-1 |
| SLES 15 SP4 | python-waitress-doc | 2.1.2-150400.12.7.1 | SUSE-SU-2024:3876-1 |
| SLES 15 SP3 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLES 15 SP2 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 3 | python-waitress +1 | 2.1.2-150400.12.7.1 | SUSE-SU-2024:3876-1 |
| SLES for SAP 15 SP4 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLES for SAP 15 SP3 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLES for SAP 15 SP2 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLE HPC 15 SP4 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1, SUSE-SU-2024:3876-1 |
| SLE HPC 15 SP4 | python-waitress-doc | 2.1.2-150400.12.7.1 | SUSE-SU-2024:3876-1 |
| SLE HPC 15 SP3 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SLE HPC 15 SP2 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SUSE Manager Server 4.3 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SUSE Manager Proxy 4.3 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
| SUSE Enterprise Storage 7.1 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-waitress | 3.0.1-1.1 | openSUSE-SU-2026:12047-1, openSUSE-SU-2024:14445-1 |
| openSUSE Leap 15.5 | python-waitress | 1.4.3-150000.3.9.1 | SUSE-SU-2024:4107-1, SUSE-SU-2024:3876-1 |
| openSUSE Leap 15.5 | python-waitress-doc | 2.1.2-150400.12.7.1 | SUSE-SU-2024:3876-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | python3-waitress | 2.1.2-1.amzn2023.0.3 | ALAS2023-2024-773 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | python-waitress | 3.0.1-1 | — |
| Azure Linux 2 (CBL-Mariner) | python-waitress | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | waitress | < 3.0.1 | 3.0.1 | GHSA-3f84-rpwh-47g6 |
Advisories 17
- WID-SEC-2024-3488 Red Hat OpenShift Container Platform: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 18, 2026
- openSUSE-SU-2026:12047-1 python313-waitress-3.0.2-1.7 on GA media SUSE / openSUSE Security Updates · Oct 5, 2026
- RHSA-2025:1192 Red Hat Security Advisory: Red Hat OpenStack Platform 17.1 (python-waitress) security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2025:1191 Red Hat Security Advisory: Red Hat OpenStack Platform 17.1 (python-waitress) security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2025:0201 Red Hat Security Advisory: Red Hat OpenStack Platform 16.2 (python-waitress) security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2024:9618 Red Hat Security Advisory: OpenShift Container Platform 4.16.23 packages and security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2024:9623 Red Hat Security Advisory: OpenShift Container Platform 4.14.41 packages and security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2024:9613 Red Hat Security Advisory: OpenShift Container Platform 4.17.5 security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2024:10815 Red Hat Security Advisory: OpenShift Container Platform 4.13.54 packages and security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2024:10535 Red Hat Security Advisory: OpenShift Container Platform 4.12.70 security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- RHSA-2024:10145 Red Hat Security Advisory: OpenShift Container Platform 4.15.39 packages and security update Red Hat Security Advisories (RHSA) · Jul 3, 2026
- USN-7115-1 Waitress vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-3955-1 waitress - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2024:3876-1 Security update for python-waitress SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14445-1 python310-waitress-3.0.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4107-1 Security update for python-waitress SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2024-773 Important: python-waitress security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Dec 16, 2024