| Name | CVE-2026-27858 |
| Description | Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory. Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. Protect access to managesieve protocol, or install fixed version. No publicly available exploits are known. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-6197-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| dovecot (PTS) | bullseye | 1:2.3.13+dfsg1-2+deb11u1 | vulnerable |
| bullseye (security) | 1:2.3.13+dfsg1-2+deb11u2 | vulnerable | |
| bookworm | 1:2.3.19.1+dfsg1-2.1+deb12u1 | vulnerable | |
| bookworm (security) | 1:2.3.19.1+dfsg1-2.1+deb12u3 | fixed | |
| trixie | 1:2.4.1+dfsg1-6+deb13u3 | vulnerable | |
| trixie (security) | 1:2.4.1+dfsg1-6+deb13u4 | fixed | |
| forky | 1:2.4.2+dfsg1-4 | vulnerable | |
| sid | 1:2.4.3+dfsg1-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| dovecot | source | bookworm | 1:2.3.19.1+dfsg1-2.1+deb12u2 | DSA-6197-1 | ||
| dovecot | source | trixie | 1:2.4.1+dfsg1-6+deb13u4 | DSA-6197-1 | ||
| dovecot | source | (unstable) | 1:2.4.3+dfsg1-1 |
https://dovecot.org/mailman3/archives/list/dovecot-news@dovecot.org/thread/IKIHZX77IPTGSP5WBIPJUOFBUQFKVPE7/
https://documentation.open-xchange.com/dovecot/security/advisories/html/2026/oxdc-adv-2026-0001.html#cve-2026-27858-managesieve-login-out-of-memory-dos
Fixed by: https://github.com/dovecot/pigeonhole/commit/54f645225a8a7911d7e16e9d50f170d217b0be95 (2.4.3)