{"id":"CVE-2026-41426","aliases":["EUVD-2026-25616","GHSA-jm8c-9f3j-4378","PYSEC-2026-109"],"status":"published","title":"pretalx: Email injection via unescaped user-controlled placeholders in pretalx mail templates","description":"pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00154,"percentile":0.0462,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-116","CWE-79"],"published":"2026-04-18T01:11:19Z","modified":"2026-11-11T23:10:00Z","fixes":[{"ecosystem":"PyPI","package":"pretalx","fixed_in":["2026.1.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"pretalx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.1.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"pretalx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.1.0"}]}],"versions":["0.1.0","0.2.0.post1","0.2.1.post1","0.2.2","0.3.0","0.3.1","0.4.0","0.4.1","0.5.0","0.6.0","0.6.1","0.7.0","0.7.1","0.8.0","0.9.0","1.0.0","1.0.1","1.0.2","1.0.3","1.0.4","1.1.0","1.1.1","1.1.2","2.0.0","2.1.0","2.1.1","2.2.0","2.3.0","2.3.1","2.3.2","2023.1.0","2023.1.1","2023.1.2","2023.1.3","2024.1.0","2024.2.0","2024.2.1","2024.3.0","2024.3.1","2025.1.0","2025.2.0","2025.2.1","2025.2.2"]},{"source":"osv","ecosystem":"PyPI","package":"pretalx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.1.0"}]}],"versions":["0.1.0","0.2.0.post1","0.2.1.post1","0.2.2","0.3.0","0.3.1","0.4.0","0.4.1","0.5.0","0.6.0","0.6.1","0.7.0","0.7.1","0.8.0","0.9.0","1.0.0","1.0.1","1.0.2","1.0.3","1.0.4","1.1.0","1.1.1","1.1.2","2.0.0","2.1.0","2.1.1","2.2.0","2.3.0","2.3.1","2.3.2","2023.1.0","2023.1.1","2023.1.2","2023.1.3","2024.1.0","2024.2.0","2024.2.1","2024.3.0","2024.3.1","2025.1.0","2025.2.0","2025.2.1","2025.2.2"]}],"products":[{"vendor":"pretalx","product":"pretalx"}],"references":[{"url":"https://github.com/pretalx/pretalx/security/advisories/GHSA-jm8c-9f3j-4378","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41426","tags":["advisory"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/pretalx/PYSEC-2026-109.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-jm8c-9f3j-4378"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41426.json","tags":["advisory"]},{"url":"https://github.com/pretalx/pretalx","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-41426","title":"pretalx: Email injection via unescaped user-controlled placeholders in pretalx mail templates","description":"pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.","status":"published","published":"2026-04-24T19:15:39.205Z","modified":"2026-04-25T01:50:38.208Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79","CWE-116"],"updated_at":"2026-11-02T13:41:08.498858Z"}],"euvd":[{"id":"EUVD-2026-25616","description":"pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.","status":"published","published":"2026-04-24T19:15:39Z","modified":"2026-04-25T01:50:38Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T19:24:18.224827Z"}],"ghsa":[{"id":"GHSA-jm8c-9f3j-4378","title":"pretalx mail templates vulnerable to email injection via unescaped user-controlled placeholders","description":"An unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector.\n\nThe same class of bug affects every mail template that interpolates a user-controlled placeholder (speaker name, proposal title, biography, question answers, etc.), including organiser-triggered emails such as acceptance/rejection notifications.\n\n### Credits\n\nThanks go to Mark Fijneman for finding and reporting a subset of this issue, which alerted us to the wider vulnerability.","status":"published","published":"2026-04-18T01:11:19Z","modified":"2026-06-08T19:03:13Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79","CWE-116"],"updated_at":"2026-11-02T14:40:18.682012Z"}],"nvd":[{"id":"CVE-2026-41426","description":"pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.","status":"published","published":"2026-04-24T20:16:27.247Z","modified":"2026-11-11T23:10:00.263Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79","CWE-116"],"updated_at":"2026-11-12T01:26:59.157514Z"}],"osv":[{"id":"CVE-2026-41426","title":"pretalx: Email injection via unescaped user-controlled placeholders in pretalx mail templates","description":"pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.","status":"published","published":"2026-04-24T19:15:39.205Z","modified":"2026-10-28T02:30:47.484539855Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-116","CWE-79"],"updated_at":"2026-11-02T15:45:03.764807Z"},{"id":"GHSA-jm8c-9f3j-4378","title":"pretalx mail templates vulnerable to email injection via unescaped user-controlled placeholders","description":"An unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector.\n\nThe same class of bug affects every mail template that interpolates a user-controlled placeholder (speaker name, proposal title, biography, question answers, etc.), including organiser-triggered emails such as acceptance/rejection notifications.\n\n### Credits\n\nThanks go to Mark Fijneman for finding and reporting a subset of this issue, which alerted us to the wider vulnerability.","status":"published","published":"2026-04-18T01:11:19Z","modified":"2026-06-08T19:15:13.810245726Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-116","CWE-79"],"updated_at":"2026-11-02T15:46:50.687609Z"},{"id":"PYSEC-2026-109","description":"pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.","status":"published","published":"2026-04-24T20:16:27.247Z","modified":"2026-05-20T09:19:11.385949Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:52:54.622769Z"}]}}