CVE Explorer
CVE-2026-41319
MailKit is a cross-platform mail client library built on top of MimeKit. A STARTTLS Response Injection vulnerability in versions prior to 4.16.0 allows a Man-in-the-Middle attacker to inject arbitrary protocol responses across the plaintext-to-TLS trust boundary, enabling SASL authentication mechanism downgrade (e.g., forcing PLAIN instead of SCRAM-SHA-256). The internal read buffer in `SmtpStream`, `ImapStream`, and `Pop3Stream` is not flushed when the underlying stream is replaced with `SslStr
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"MailKit","vendor":"jstedfast","versions":[{"status":"affected","version":"< 4.16.0"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:e789ca27c5d9d8fc0798e8fc856a0899e002110229eedf9d1d6eac077c3bdffc · sha256:a612bb67b619db66… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:e789ca27c5d9d8fc0798e8fc856a0899e002110229eedf9d1d6eac077c3bdffc · sha256:a612bb67b619db66… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-74","description":"CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:e789ca27c5d9d8fc0798e8fc856a0899e002110229eedf9d1d6eac077c3bdffc · sha256:a612bb67b619db66… · /containers/cna/problemTypes/0/descriptions/0
Source references
2 source assertions{"tags":["exploit"],"url":"https://github.com/jstedfast/MailKit/security/advisories/GHSA-9j88-vvj5-vhgr"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:e789ca27c5d9d8fc0798e8fc856a0899e002110229eedf9d1d6eac077c3bdffc · sha256:a612bb67b619db66… · /containers/adp/0/references/0
{"name":"https://github.com/jstedfast/MailKit/security/advisories/GHSA-9j88-vvj5-vhgr","tags":["x_refsource_CONFIRM"],"url":"https://github.com/jstedfast/MailKit/security/advisories/GHSA-9j88-vvj5-vhgr"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:e789ca27c5d9d8fc0798e8fc856a0899e002110229eedf9d1d6eac077c3bdffc · sha256:a612bb67b619db66… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.