Detections
Analytics
CVE-2026-27858
high
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.
References
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27858.json
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
https://bugzilla.redhat.com/show_bug.cgi?id=2452175
https://access.redhat.com/security/cve/CVE-2026-27858
https://access.redhat.com/errata/RHSA-2026:26564
https://access.redhat.com/errata/RHSA-2026:19455
https://access.redhat.com/errata/RHSA-2026:19453
https://access.redhat.com/errata/RHSA-2026:19364
https://access.redhat.com/errata/RHSA-2026:19149
https://access.redhat.com/errata/RHSA-2026:18053
https://access.redhat.com/errata/RHSA-2026:17630
https://access.redhat.com/errata/RHSA-2026:17628
https://access.redhat.com/errata/RHSA-2026:17626
https://access.redhat.com/errata/RHSA-2026:17625
https://access.redhat.com/errata/RHSA-2026:17602
https://access.redhat.com/errata/RHSA-2026:13857