CVE-2026-086520.01.2026, 22:15User-controlled header names and values containing newlines can allow injecting HTTP headers.InjectionEnginsightProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVectorNISTNISTUNKNOWN---PSFCNA------Base ScoreCVSS 3.xEPSS ScorePercentile: UnknownCommon Weakness EnumerationCWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')The software constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.Referenceshttps://github.com/python/cpython/commit/22e4d55285cee52bc4dbe061324e5f30bd4dee58https://github.com/python/cpython/commit/23e3c0ae867cca0130e441e776c9955b9027c510https://github.com/python/cpython/commit/2f840249550e082dc351743f474ba56da10478d2https://github.com/python/cpython/commit/4802b96a2cde58570c24c13ef3289490980961c5https://github.com/python/cpython/commit/e4846a93ac07a8ae9aa18203af0dd13d6e7a6995https://github.com/python/cpython/commit/f7fceed79ca1bceae8dbe5ba5bc8928564da7211https://github.com/python/cpython/issues/143916https://github.com/python/cpython/pull/143917https://mail.python.org/archives/list/security-announce@python.org/thread/BJ6QPHNSHJTS3A7CFV6IBMCAP2DWRVNT/