CVE-2018-12551
Users who have only used the mosquitto_passwd utility to create and modify their password files are unaffected by this vulnerability.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for authentication, any malformed data in the password file will be treated as valid. This typically means that the malformed data becomes a username and no password. If this occurs, clients can circumvent authentication and get access to the broker by using the malformed username. In particular, a blank line will be treated as a valid empty username. Other security measures are unaffected. Users who have only used the mosquitto_passwd utility to create and modify their password files are unaffected by this vulnerability.
- CVSS 3.0
- 8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.47% probability · 74th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-703, CWE-287
- Affected
- eclipse/mosquitto
- Source
- emo@eclipse.org
EPSS 1.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=543401Exploit, Issue Tracking, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2019/10/msg00035.html
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=543401Exploit, Issue Tracking, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2019/10/msg00035.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.