mailcow: dockerized vulnerable to stored XSS in autodiscover logs email address field
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the admin dashboard's Autodiscover logs render the EMailAddress value (logged as the "user" field) without HTML escaping. By submitting an unauthenticated Autodiscover request with a crafted EMailAddress containing HTML/JS, the payload is stored in Redis and executed when an admin views the Autodiscover logs. Version 2026-03b fixes the vulnerability.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-40872
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 17:17 UTC · Revision 1
Source evidence
mailcow: dockerized vulnerable to stored XSS in autodiscover logs email address field
core-osv · Original sourcePublished 21 Apr 2026, 19:14 UTC
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the admin dashboard's Autodiscover logs render the EMailAddress value (logged as the "user" field) without HTML escaping. By submitting an unauthenticated Autodiscover request with a crafted EMailAddress containing HTML/JS, the payload is stored in Redis and executed when an admin views the Autodiscover logs. Version 2026-03b fixes the vulnerability.
osv:CVE-2026-40872
Complete source record
{
"id": "792bdfee98d3334789462536972a2f56f9174f0dd4eedf4011ebbcba81dde138",
"url": "https://osv.dev/vulnerability/CVE-2026-40872",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "mailcow: dockerized vulnerable to stored XSS in autodiscover logs email address field",
"summary": "mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the admin dashboard's Autodiscover logs render the EMailAddress value (logged as the \"user\" field) without HTML escaping. By submitting an unauthenticated Autodiscover request with a crafted EMailAddress containing HTML/JS, the payload is stored in Redis and executed when an admin views the Autodiscover logs. Version 2026-03b fixes the vulnerability.",
"evidence": "osv:CVE-2026-40872",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2026-40872",
"aliases": [
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"GHSA-f9xf-vc72-rcgm"
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"metrics": [
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"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N"
}
],
"affected": [
{
"ranges": [
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"type": "GIT",
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"extracted_events": [
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{
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"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
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{
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"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40872.json"
}
}
],
"modified": "2026-10-28T02:30:38.143352083Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40872.json",
"https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-f9xf-vc72-rcgm",
"https://nvd.nist.gov/vuln/detail/CVE-2026-40872"
],
"provider_metadata": {
"cwe_ids": [
"CWE-79",
"CWE-80"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40872.json"
}
},
"related_cves": [
{
"value": "CVE-2026-40872",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 505241,
"published_at": "2026-04-21T19:14:45.309+00:00"
}