{"id":"CVE-2026-13163","aliases":["EUVD-2026-38759","GHSA-wfgr-g7h2-c6m6"],"status":"published","title":"Lack of input validation in Mailerup input parameter leads to Open Redirect","description":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c/\u003ctoken\u003e/) in Mailerup \u003c1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0051,"percentile":0.44018,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-601"],"published":"2026-06-24T12:49:05Z","modified":"2026-11-11T10:31:02Z","products":[{"vendor":"mailerup","product":"mailerup"}],"references":[{"url":"https://github.com/Maalfer/mailerup/commit/99eb6d4586134bf3f4422093fbf47d6794ef0ee5","tags":["patch","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-13163","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-wfgr-g7h2-c6m6"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13163.json","tags":["advisory"]},{"url":"https://github.com/Maalfer/mailerup","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-13163","title":"Lack of input validation in Mailerup input parameter leads to Open Redirect","description":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c/\u003ctoken\u003e/) in Mailerup \u003c1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.","status":"published","published":"2026-06-24T12:49:05.227Z","modified":"2026-06-24T13:07:07.003Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:19:50.24628Z"}],"euvd":[{"id":"EUVD-2026-38759","description":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c/\u003ctoken\u003e/) in Mailerup \u003c1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.","status":"published","published":"2026-06-24T12:49:05Z","modified":"2026-06-24T13:07:07Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:20:31.123469Z"}],"ghsa":[{"id":"GHSA-wfgr-g7h2-c6m6","title":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking...","description":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c/\u003ctoken\u003e/) in Mailerup \u003c1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.","status":"published","published":"2026-06-24T15:31:45Z","modified":"2026-06-24T15:31:45Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T15:08:58.190411Z"}],"nvd":[{"id":"CVE-2026-13163","description":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c/\u003ctoken\u003e/) in Mailerup \u003c1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.","status":"published","published":"2026-06-24T13:16:31.993Z","modified":"2026-10-24T13:10:00.147Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:12:25.288279Z"}],"osv":[{"id":"CVE-2026-13163","title":"Lack of input validation in Mailerup input parameter leads to Open Redirect","description":"Open redirect vulnerability (CWE-601) in the _safe_redirect function of the click-tracking endpoint (/c/\u003ctoken\u003e/) in Mailerup \u003c1.0.0 on all platforms allows remote unauthenticated attackers to redirect victims to arbitrary external sites and conduct phishing attacks via a crafted u query parameter, because the URL scheme is validated (blocking javascript: and data:) but the destination host is not restricted to an allowlist, and a signing.BadSignature exception is silently caught so a valid signed token is not required.","status":"published","published":"2026-06-24T12:49:05.227Z","modified":"2026-11-11T10:31:02.428952931Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-11T11:06:41.417773Z"}]}}