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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
AlmaLinux Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | dovecot-pigeonhole-2.3.16-15.el9_7.1.aarch64.rpm |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 1:2.4.1+dfsg1-6+deb13u4 |
| sid | Fixed | 1:2.4.3+dfsg1-1 |
| forky | Fixed | 1:2.4.3+dfsg1-1 |
| bullseye | Fixed | 1:2.3.13+dfsg1-2+deb11u3 |
| bookworm | Fixed | 1:2.3.19.1+dfsg1-2.1+deb12u2 |
Red Hat Fixed 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | — |
| 8 | Fixed | — |
Rocky Linux Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| 9 | Fixed | — |
References
- https://access.redhat.com/errata/RHSA-2026:13857
- https://access.redhat.com/errata/RHSA-2026:19364
- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json
- https://security-tracker.debian.org/tracker/CVE-2026-27858
- https://www.suse.com/security/cve/CVE-2026-27858.html
- https://access.redhat.com/errata/RHSA-2026:13830
- https://bugzilla.redhat.com/2452172
- https://bugzilla.redhat.com/2452175
- https://bugzilla.redhat.com/2452179
- https://errata.almalinux.org/8/ALSA-2026-13830.html
- https://errata.almalinux.org/9/ALSA-2026-13857.html
- https://errata.almalinux.org/9/ALSA-2026-19364.html
- https://errata.rockylinux.org/RLSA-2026:13857
CWEs
CWE-400
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.