CVE-2026-27858Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-400, CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Jul 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
dovecot dovecot dovecot:dovecot | before 2.4.3 | NVD |
open-xchange dovecot open-xchange:dovecot | before 2.3.22.1; from 3.0.0 before 3.0.5; from 3.1.0 before 3.1.4 | NVD |
References
- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.jsonvendor-advisory
- https://access.redhat.com/errata/RHSA-2026:13498
- https://access.redhat.com/errata/RHSA-2026:13830
- https://access.redhat.com/errata/RHSA-2026:13857
- https://access.redhat.com/errata/RHSA-2026:17602
- https://access.redhat.com/errata/RHSA-2026:17625
- https://access.redhat.com/errata/RHSA-2026:17626
- https://access.redhat.com/errata/RHSA-2026:17628
- https://access.redhat.com/errata/RHSA-2026:17630
- https://access.redhat.com/errata/RHSA-2026:18053
- https://access.redhat.com/errata/RHSA-2026:19149
- https://access.redhat.com/errata/RHSA-2026:19364
- https://access.redhat.com/errata/RHSA-2026:19453
- https://access.redhat.com/errata/RHSA-2026:19455
- https://access.redhat.com/errata/RHSA-2026:26564
- https://access.redhat.com/security/cve/CVE-2026-27858
- https://bugzilla.redhat.com/show_bug.cgi?id=2452175
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27858.json
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.