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Fencer Vulns
medium 6.5

CVE-2022-31015 json

Uncaught Exception (due to a data race) leads to process termination in Waitress

published 2022-05-31 4 y ago modified 2026-06-17 4 mo ago also GHSA-f5x9-8jwc-25rw , PYSEC-2022-205 , EUVD-2022-0359

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

Waitress is a Web Server Gateway Interface server for Python 2 and 3. Waitress versions 2.1.0 and 2.1.1 may terminate early due to a thread closing a socket while the main thread is about to call select(). This will lead to the main thread raising an exception that is not handled and then causing the entire application to be killed. This issue has been fixed in Waitress 2.1.2 by no longer allowing the WSGI thread to close the socket. Instead, that is always delegated to the main thread. There is no work-around for this issue. However, users using waitress behind a reverse proxy server are less likely to have issues if the reverse proxy always reads the full response.

Patch / fix

  • pypi waitress 2.1.2
  • agendaless waitress 2.1.2
  • waitress Debian 14, Debian 13, Debian 12 2.1.2-1

debian advisories DEBIAN-CVE-2022-31015

  • python-waitress openSUSE Tumbleweed 3.0.2-1.4

opensuse advisories openSUSE-SU-2025:15108-1

  • py3-waitress Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 2.1.2-r0

alpine advisories ALPINE-CVE-2022-31015

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-waitress Azure Linux 3.0 3.0.1-1

azure linux advisories AZL-44571

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-31015 updated cvss 5.3

waitress: uncaught Exception (due to a data race) leads to process termination

  • Red Hat Ceph Storage 3 python-waitress Red Hat Ceph Storage 4 python-waitress, python3-waitress Red Hat Ceph Storage 5 python-waitress Red Hat Ceph Storage 7 python-waitress Red Hat Openshift Container Storage 4 python-waitress Red Hat Openshift Data Foundation 4 python-waitress
    +4 more products
    Red Hat OpenStack Platform 13 (Queens) python-waitress, python2-waitress Red Hat OpenStack Platform 16.1 python-waitress, python3-waitress Red Hat OpenStack Platform 16.2 python-waitress, python3-waitress Red Hat Quay 3 quay/quay-rhel8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

1.50% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Pylons/waitress/issues/374 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi waitress
>=2.1.0, <2.1.2
2.1.2

Affected products

  • Pylons waitress

Classification

Weakness
  • CWE-248 Uncaught Exception
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.