SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-12550

When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL file is empty, or contains only comments or blank lines, then Mosquitto will treat this as though no ACL file has been defined and use a default allow…

HIGH 8.1EPSS 1.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.35%). 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 an ACL file, and that ACL file is empty, or contains only comments or blank lines, then Mosquitto will treat this as though no ACL file has been defined and use a default allow policy. The new behaviour is to have an empty ACL file mean that all access is denied, which is not a useful configuration but is not unexpected.

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
1.35% probability · 71th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-440
Affected
eclipse/mosquitto
Source
emo@eclipse.org
EPSS trend
0%3%5%27 October 2026: 1.35%27 October 202627 October 2026

EPSS 1.4% 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.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.