Security advisory
An issue was discovered in Cyrus IMAP before 3.12.4. Mailbox/set let a sharee change a special-use role on shared mailboxes. An authenticated user with maySetKeywords on another user's mailbox could change that mailbox's specialuse annotation. This could allow the sharee to change the shared mailbox to perform the archived, snoozed, or other role, which might cause mail mail to be written to the shared mailbox, sharing more content than intended. (This is likely to be an unusual situation, made more unusual because if the target already has an non-shared mailbox with that role, role duplication suppression will prevent the update.)
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-61910
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 12:28 UTC · Revision 1
Source evidence
An issue was discovered in Cyrus IMAP before 3.12.4. Mailbox/set let a sharee change a special-use role on shared mailboxes. An authenticated user with maySetKeywords on another user's mailbox could change that mailbox's specialuse annotation. This could allow the sharee to change the shared mailbox to perform the archived, snoozed, or other role, which might cause mail mail to be written to the shared mailbox, sharing more content than intended. (This is likely to be an unusual situation, made more unusual because if the target already has an non-shared mailbox with that role, role duplication suppression will prevent the update.)
osv:CVE-2026-61910
Complete source record
{
"id": "4e39a9eb5680fe38980f1b5170a91bbbd8cfe03414d8ac4bb66ae6280533873c",
"url": "https://osv.dev/vulnerability/CVE-2026-61910",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-61910",
"summary": "An issue was discovered in Cyrus IMAP before 3.12.4. Mailbox/set let a sharee change a special-use role on shared mailboxes. An authenticated user with maySetKeywords on another user's mailbox could change that mailbox's specialuse annotation. This could allow the sharee to change the shared mailbox to perform the archived, snoozed, or other role, which might cause mail mail to be written to the shared mailbox, sharing more content than intended. (This is likely to be an unusual situation, made more unusual because if the target already has an non-shared mailbox with that role, role duplication suppression will prevent the update.)",
"evidence": "osv:CVE-2026-61910",
"products": [],
"severity": "low",
"structured": {
"id": "CVE-2026-61910",
"aliases": [
"CVE-2026-61910"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/cyrusimap/cyrus-imapd",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "08031fd42e027bdb5bc286e428a03e1c53c2e105"
},
{
"fixed": "ad6d4e67d0edbdf99e7ce31658c67640f30479c4"
},
{
"fixed": "f8ffbe4a87455c591fe355b03a2713a50f8441ab"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:cyrus:imap:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "3.8.8"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:cyrus:imap:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.9.0"
},
{
"fixed": "3.10.4"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:cyrus:imap:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.11.0"
},
{
"fixed": "3.12.4"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"cyrus-imapd-3.8.7",
"cyrus-imapd-3.10.3",
"cyrus-imapd-3.12.3",
"cyrus-imapd-3.12.2",
"cyrus-imapd-3.8.6",
"cyrus-imapd-3.10.2",
"cyrus-imapd-3.12.1",
"cyrus-imapd-3.12.0",
"cyrus-imapd-3.12.0-rc1",
"cyrus-imapd-3.12.0-beta2",
"cyrus-imapd-3.8.5",
"cyrus-imapd-3.12.0-beta1",
"cyrus-imapd-3.10.1",
"cyrus-imapd-3.12.0-alpha0",
"cyrus-imapd-3.10.0",
"cyrus-imapd-3.8.4",
"cyrus-imapd-3.10.0-rc2",
"cyrus-imapd-3.8.3",
"cyrus-imapd-3.10.0-rc1",
"cyrus-imapd-3.8.2",
"cyrus-imapd-3.10.0-beta2",
"cyrus-imapd-3.10.0-beta1",
"cyrus-imapd-3.11.0-alpha0",
"cyrus-imapd-3.10.0-alpha0",
"cyrus-imapd-3.8.1",
"cyrus-imapd-3.8.0",
"cyrus-imapd-3.8.0-rc1",
"cyrus-imapd-3.8.0-beta2",
"cyrus-imapd-3.8.0-beta1",
"cyrus-imapd-3.9.0-alpha0",
"cyrus-imapd-3.8.0-alpha0",
"cyrus-imapd-3.7.0-alpha0",
"cyrus-imapd-3.5.0-alpha0",
"cyrus-imapd-3.3.1",
"cyrus-imapd-3.3.0",
"cyrus-imapd-3.3.0-dev0",
"cyrus-imapd-3.1.9",
"cyrus-imapd-3.1.8",
"cyrus-imapd-3.1.7",
"cyrus-imapd-3.1.6",
"cyrus-imapd-3.1.5",
"cyrus-imapd-3.1.4",
"cyrus-imapd-3.1.3",
"cyrus-imapd-3.1.2",
"cyrus-imapd-3.1.1",
"cyrus-imapd-3.0.0-rc4",
"cyrus-imapd-3.1.0-dev",
"cyrus-imapd-3.0.0-rc3",
"cyrus-imapd-3.0.0-rc2",
"cyrus-imapd-3.0.0-rc1",
"cyrus-imapd-3.0.0-beta6",
"cyrus-imapd-3.0.0-beta5",
"cyrus-imapd-3.0.0-beta4",
"cyrus-imapd-3.0.0-beta3",
"cyrus-imapd-3.0.0-beta2",
"cyrus-imapd-3.0.0-beta1",
"posttab",
"pretab",
"cyrus-imapd-2.5-snapshot-autoconf-and-automake",
"cyrus-imapd-2.4.2",
"cyrus-imapd-2.4.1",
"cyrus-imapd-2.4.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61910.json"
}
}
],
"modified": "2026-10-28T02:30:28.539779562Z",
"provider": "osv",
"references": [
"https://cyrusimap.org",
"https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html",
"https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html",
"https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61910.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-61910"
],
"provider_metadata": {
"cwe_ids": [
"CWE-863"
],
"cna_assigner": "mitre",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"fixed": "3.8.8"
},
{
"introduced": "3.9.0"
},
{
"fixed": "3.10.4"
},
{
"introduced": "3.11.0"
},
{
"fixed": "3.12.4"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61910.json"
}
},
"related_cves": [
{
"value": "CVE-2026-61910",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 495391,
"published_at": "2026-09-09T00:00:00+00:00"
}