ALPINE-CVE-2026-40203
When IMAP compression is enabled, the same compression state is reused across responses in a session, so response sizes depend on both attacker-supplied mail and other mail in the same mailbox. An attacker that can send mail to a user and can also observe the sizes of that user's IMAP traffic can confirm whether the body of a small message matches a guessed text. Recovery of arbitrary unknown content was not demonstrated, but the attack can disclose whether a secret-like message body matches a candidate. Disable IMAP compression. Update to non-vulnerable version. No publicly available exploits are known.
ALPINE-CVE-2026-40203
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:ALPINE-CVE-2026-40203
dovecot
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.4.5-r0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
dovecot
Source reference: /affected/1/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2.4.5-r0
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.4.5-r0"
}
]
}
],
"package": {
"name": "dovecot",
"purl": "pkg:apk/alpine/dovecot?arch=source",
"ecosystem": "Alpine:v3.23"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-40203.json"
},
"ecosystem_specific": {}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.4.5-r0"
}
]
}
],
"package": {
"name": "dovecot",
"purl": "pkg:apk/alpine/dovecot?arch=source",
"ecosystem": "Alpine:v3.24"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-40203.json"
},
"ecosystem_specific": {}
}
]Publisher severity
No explicit severity was provided.
- Event
- #54341 · Revision 1
- Added to Heist Feed
- Publisher date