CVE-2026-27857 PUBLISHED

Assigner: OX
Reserved: 24.02.2026 Published: 27.03.2026 Updated: 27.03.2026

Sending "NOOP (((...)))" command with 4000 parenthesis open+close results in ~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for longer time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Install fixed version, there is no other remediation. No publicly available exploits are known.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 4.3

Product Status

Vendor Open-Xchange GmbH
Product OX Dovecot Pro
Versions Default: unaffected
  • affected from 0 to 2.3.0 (incl.)

References

Problem Types

  • Uncontrolled Resource Consumption cwe