{"id":"CVE-2026-1299","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-1299","generatedAt":"2026-10-28T00:28:32.182Z","title":"The email module, specifically the \"BytesGenerator\" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized.","description":"The \nemail module, specifically the \"BytesGenerator\" class, didn’t properly quote newlines for email headers when \nserializing an email message allowing for header injection when an email\n is serialized. This is only applicable if using \"LiteralHeader\" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in \"BytesGenerator\".","published":"2026-01-23T17:16:13.000Z","lastModified":"2026-06-17T10:15:29.000Z","status":"Deferred","sourceIdentifier":"cna@python.org","cvss":{"version":"4.0","score":6,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/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/M"},"cwe":["CWE-93"],"affected":[],"epss":{"score":0.00573,"percentile":0.47102,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.57%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://cve.org/CVERecord?id=CVE-2024-6923","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36","source":"cna@python.org"},{"url":"https://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831a","source":"cna@python.org"},{"url":"https://github.com/python/cpython/issues/144125","source":"cna@python.org"},{"url":"https://github.com/python/cpython/pull/144126","source":"cna@python.org"},{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/","source":"cna@python.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-1299","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}