When a client is in monitoring mode, the regex begin used to detected monitor messages could cause exponential backtracking on some strings. This issue could lead to a denial of service.
// patches
The problem was fixed in commit 2d11b6d and was released in version 3.1.1.
// cvss v3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Checked 2026-11-06 at 21:31 UTC. The most recent advisory here was published 2021-04-27. Updated continuously from NVD, GHSA, OSV and CNA feeds.