SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-0938

The Python standard library functions `urllib.parse.urlsplit` and `urlparse` accepted domain names that included square brackets which isn't valid according to RFC 3986.

MEDIUM 6.3EPSS 1.56%

Does this matter?

Lower severity and a low EPSS score (1.56%). Track it; it rarely justifies an emergency change on its own.

Description

The Python standard library functions `urllib.parse.urlsplit` and `urlparse` accepted domain names that included square brackets which isn't valid according to RFC 3986. Square brackets are only meant to be used as delimiters for specifying IPv6 and IPvFuture hosts in URLs. This could result in differential parsing across the Python URL parser and other specification-compliant URL parsers.

CVSS 4.0
6.3 MEDIUMCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
1.56% probability · 74th percentile
CISA KEV
Not listed
Weakness
CWE-20
Source
cna@python.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.