Encode newlines in headers when using ByteGenerator · Issue #144125 · python/cpython · GitHub

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Encode newlines in headers when using ByteGenerator #144125

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Encode newlines in headers when using ByteGenerator#144125

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stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directorytopic-emailtype-securityA security issueA security issue

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sethmlarson

opened on Jan 21, 2026

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Related:

• CVE-2024-6923
• email.policy.default - gotcha with re-using parsed headers with embedded newlines #121650

Linked PRs

• gh-144125: email: verify headers are sound in BytesGenerator #144126
• [3.10] gh-144125: email: verify headers are sound in BytesGenerator #144180
• [3.13] gh-144125: email: verify headers are sound in BytesGenerator #144181
• [3.14] gh-144125: email: verify headers are sound in BytesGenerator #144182
• [3.12] gh-144125: email: verify headers are sound in BytesGenerator #144188
• [3.11] gh-144125: email: verify headers are sound in BytesGenerator #144189

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stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directorytopic-emailtype-securityA security issueA security issue

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