SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-18765

An exploitable arbitrary memory read vulnerability exists in the MQTT packet-parsing functionality of Cesanta Mongoose 6.13.

CRITICAL 9.1EPSS 1.84%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.84%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An exploitable arbitrary memory read vulnerability exists in the MQTT packet-parsing functionality of Cesanta Mongoose 6.13. It is a heap-based buffer over-read in mg_mqtt_next_subscribe_topic. A specially crafted MQTT SUBSCRIBE packet can cause an arbitrary out-of-bounds memory read potentially resulting in information disclosure and denial of service. An attacker needs to send a specially crafted MQTT packet over the network to trigger this vulnerability.

CVSS 3.0
9.1 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
1.84% probability · 79th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-125
Affected
cesanta/mongoose
Source
cve@mitre.org
EPSS trend
0%3%5%27 October 2026: 1.84%27 October 202627 October 2026

EPSS 1.8% 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.