SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2022-31015

This issue has been fixed in Waitress 2.1.2 by no longer allowing the WSGI thread to close the socket.

MEDIUM 5.9EPSS 1.50%

Does this matter?

Lower severity and a low EPSS score (1.50%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.50% probability · 74th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-248, CWE-362
Affected
agendaless/waitress
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 1.50%26 October 202626 October 2026

EPSS 1.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.