Critical (9.8). EPSS 3.3% chance of exploitation in the next 30 days. Fixed in twisted 20.3.0, 20.3.0rc1.
In Twisted Web through 19.10.0, there was an HTTP request splitting vulnerability. When presented with a content-length and a chunked encoding header, the content-length took precedence and the remainder of the request body was interpreted as a pipelined request.
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
3.3% chance of exploitation in the next 30 days; higher than 88% of CVEs (scores of 2026-10-31)