{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23829", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-01-16T15:46:40.841Z", "datePublished": "2026-01-18T23:23:04.176Z", "dateUpdated": "2026-01-20T20:08:41.935Z"}, "containers": {"cna": {"title": "Mailpit has SMTP Header Injection via Regex Bypass", "problemTypes": [{"descriptions": [{"cweId": "CWE-93", "lang": "en", "description": "CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-150", "lang": "en", "description": "CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/axllent/mailpit/security/advisories/GHSA-54wq-72mp-cq7c", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/axllent/mailpit/security/advisories/GHSA-54wq-72mp-cq7c"}, {"name": "https://github.com/axllent/mailpit/commit/36cc06c125954dec6673219dafa084e13cc14534", "tags": ["x_refsource_MISC"], "url": "https://github.com/axllent/mailpit/commit/36cc06c125954dec6673219dafa084e13cc14534"}, {"name": "https://github.com/axllent/mailpit/releases/tag/v1.28.3", "tags": ["x_refsource_MISC"], "url": "https://github.com/axllent/mailpit/releases/tag/v1.28.3"}], "affected": [{"vendor": "axllent", "product": "mailpit", "versions": [{"version": "< 1.28.3", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-01-19T18:59:54.087Z"}, "descriptions": [{"lang": "en", "value": "Mailpit is an email testing tool and API for developers. Prior to version 1.28.3, Mailpit's SMTP server is vulnerable to Header Injection due to an insufficient Regular Expression used to validate `RCPT TO` and `MAIL FROM` addresses. An attacker can inject arbitrary SMTP headers (or corrupt existing ones) by including carriage return characters (`\\r`) in the email address. This header injection occurs because the regex intended to filter control characters fails to exclude `\\r` and `\\n` when used inside a character class. Version 1.28.3 fixes this issue."}], "source": {"advisory": "GHSA-54wq-72mp-cq7c", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-01-20T20:08:32.596156Z", "id": "CVE-2026-23829", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-20T20:08:41.935Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-23829", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-01-20T20:08:32.596156Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-20T20:08:37.547Z"}}], "cna": {"title": "Mailpit has SMTP Header Injection via Regex Bypass", "source": {"advisory": "GHSA-54wq-72mp-cq7c", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}], "affected": [{"vendor": "axllent", "product": "mailpit", "versions": [{"status": "affected", "version": "< 1.28.3"}]}], "references": [{"url": "https://github.com/axllent/mailpit/security/advisories/GHSA-54wq-72mp-cq7c", "name": "https://github.com/axllent/mailpit/security/advisories/GHSA-54wq-72mp-cq7c", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/axllent/mailpit/commit/36cc06c125954dec6673219dafa084e13cc14534", "name": "https://github.com/axllent/mailpit/commit/36cc06c125954dec6673219dafa084e13cc14534", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/axllent/mailpit/releases/tag/v1.28.3", "name": "https://github.com/axllent/mailpit/releases/tag/v1.28.3", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "Mailpit is an email testing tool and API for developers. Prior to version 1.28.3, Mailpit's SMTP server is vulnerable to Header Injection due to an insufficient Regular Expression used to validate `RCPT TO` and `MAIL FROM` addresses. An attacker can inject arbitrary SMTP headers (or corrupt existing ones) by including carriage return characters (`\\r`) in the email address. This header injection occurs because the regex intended to filter control characters fails to exclude `\\r` and `\\n` when used inside a character class. Version 1.28.3 fixes this issue."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-93", "description": "CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-150", "description": "CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-01-19T18:59:54.087Z"}}}, "cveMetadata": {"cveId": "CVE-2026-23829", "state": "PUBLISHED", "dateUpdated": "2026-01-20T20:08:41.935Z", "dateReserved": "2026-01-16T15:46:40.841Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-01-18T23:23:04.176Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Mailpit is an email testing tool and API for developers. Prior to version 1.28.3, Mailpit's SMTP server is vulnerable to Header Injection due to an insufficient Regular Expression used to validate `RCPT TO` and `MAIL FROM` addresses. An attacker can inject arbitrary SMTP headers (or corrupt existing ones) by including carriage return characters (`\\r`) in the email address. This header injection occurs because the regex intended to filter control characters fails to exclude `\\r` and `\\n` when used inside a character class. Version 1.28.3 fixes this issue."}], "id": "CVE-2026-23829", "lastModified": "2026-01-19T19:16:03.837", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-01-19T00:15:48.707", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/axllent/mailpit/commit/36cc06c125954dec6673219dafa084e13cc14534"}, {"source": "security-advisories@github.com", "url": "https://github.com/axllent/mailpit/releases/tag/v1.28.3"}, {"source": "security-advisories@github.com", "url": "https://github.com/axllent/mailpit/security/advisories/GHSA-54wq-72mp-cq7c"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-93"}, {"lang": "en", "value": "CWE-150"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"created": "2026-01-19T09:19:06.164211+00:00", "updated": "2026-01-19T09:19:06.164239+00:00", "vendors": ["axllent", "axllent$PRODUCT$mailpit"]}