CVE-2026-27858

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Open-Xchange GmbHOX Dovecot Pro0 <= 2.3.0affected
Open-Xchange GmbHOX Dovecot Pro0 <= 3.1.0affected
Open-Xchange GmbHOX Dovecot Pro0 <= 2.4.0affected

Weaknesses

  • CWE-400: Uncontrolled Resource Consumption

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

dovecot: denial of service via crafted message before authentication

Additional References

References