{"id":"CVE-2026-40873","aliases":["EUVD-2026-24255","GHSA-2xjc-rg88-jvpp"],"status":"published","title":"mailcow: dockerized vulnerable to stored XSS in Quarantine attachment filenames","description":"mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.","severity":{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0042,"percentile":0.36732,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79","CWE-80"],"published":"2026-04-21T19:15:39Z","modified":"2026-10-28T02:31:07Z","products":[{"vendor":"mailcow","product":"mailcow-dockerized"}],"references":[{"url":"https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-2xjc-rg88-jvpp","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40873.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40873","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-40873","title":"mailcow: dockerized vulnerable to stored XSS in Quarantine attachment filenames","description":"mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.","status":"published","published":"2026-04-21T19:15:39.046Z","modified":"2026-04-21T19:39:19.981Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-79","CWE-80"],"updated_at":"2026-11-02T13:43:11.445168Z"}],"euvd":[{"id":"EUVD-2026-24255","description":"mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.","status":"published","published":"2026-04-21T19:15:39Z","modified":"2026-04-21T19:39:19Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N","level":"high"}],"updated_at":"2026-11-02T19:24:21.512647Z"}],"nvd":[{"id":"CVE-2026-40873","description":"mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.","status":"published","published":"2026-04-21T20:17:00.82Z","modified":"2026-10-26T21:10:00.17Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/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":"high","assessor":"secondary"}],"cwes":["CWE-79","CWE-80"],"updated_at":"2026-11-02T14:12:15.493943Z"}],"osv":[{"id":"CVE-2026-40873","title":"mailcow: dockerized vulnerable to stored XSS in Quarantine attachment filenames","description":"mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.","status":"published","published":"2026-04-21T19:15:39.046Z","modified":"2026-10-28T02:31:07.589696729Z","cvss":[{"version":"4.0","score":8.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N","level":"high"}],"cwes":["CWE-79","CWE-80"],"updated_at":"2026-11-02T15:45:03.424067Z"}]}}