{"schemaVersion":3,"id":"CVE-2026-93576","aliases":["UBUNTU-CVE-2026-93576","DEBIAN-CVE-2026-93576"],"status":"published","duplicateOf":null,"title":null,"description":"A flaw was found in Netty netty-codec-smtp. The component does not properly validate Carriage Return (CR) and Line Feed (LF) characters in the SMTP command-name field. A remote attacker, if an application routes untrusted input into this field, can embed CR/LF characters to inject arbitrary SMTP commands. This can lead to SMTP command smuggling, allowing for unauthorized email relay or spoofing of sender/recipient addresses. While the impact is significant, the real-world exploitability is considered lower as applications typically do not place user-controlled data in the command-name field.","dates":{"published":"2026-09-18T14:33:20.473Z","modified":"2026-09-25T08:29:13.508Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.0027,"percentile":0.1798,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0.0010000000000000026,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.00269},"history":[{"date":"2026-09-19T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0027,"percentile":0.1798}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00269,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00463,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0027,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0027,"percentile":0.1798}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-93","name":"Improper Neutralization of CRLF Sequences ('CRLF Injection')","description":"The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/93.html"}],"affected":[{"vendor":"debian","product":"netty","name":"netty","label":"netty","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/netty","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"netty","name":"netty","label":"netty","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/netty","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-93576","label":"access.redhat.com/security/cve/CVE-2026-93576","hostname":"access.redhat.com","tags":["VDB Entry","X Refsource REDHAT","REPORT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2536968","label":"bugzilla.redhat.com/show_bug.cgi?id=2536968","hostname":"bugzilla.redhat.com","tags":["Issue Tracking","X Refsource REDHAT","REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-93576","label":"ubuntu.com/security/CVE-2026-93576","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-93576","label":"www.cve.org/CVERecord?id=CVE-2026-93576","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://github.com/netty/netty/security/advisories/GHSA-5vh9-c45f-rf7p","label":"github.com/netty/netty/security/advisories/GHSA-5vh9-c45f-rf7p","hostname":"github.com","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-93576","label":"security-tracker.debian.org/tracker/CVE-2026-93576","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2026:11882-1","SUSE-SU-2026:4391-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:11882-1","SUSE-SU-2026:4391-1"]},"timeline":[{"kind":"published","date":"2026-09-18T14:33:20.473Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-25T08:29:13.508Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":30,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T17:02:01.764Z","stale":false,"partial":false}}