Description
CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.
References10
- github.com/python/cpython/commit/05ed7ce7ae9e17c23a04085b2539fe…
- github.com/python/cpython/commit/56b7100b04e44ea27989242b176beb…
- github.com/python/cpython/commit/58703ec1bdd1eb075e8b01a0c42768…
- github.com/python/cpython/commit/9e071c9b28c17f347f81b388a003d4…
- github.com/python/cpython/commit/b1cf9016335cb637c5a425032e8274…
- github.com/python/cpython/commit/c00c386faa579ad71196d334086444…
- github.com/python/cpython/issues/146211
- github.com/python/cpython/pull/146212
- mail.python.org/archives/list/[email protected]/thre…
- www.openwall.com/lists/oss-security/2026/04/11/4
Metrics
- CVSS 4.0
-
5.7
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 46 · as of 12 November 2026
- CWE
- CWE-93
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.