CVE-2026-54412
Summary
| CVE | CVE-2026-54412 |
|---|---|
| State | PUBLISHED |
| Assigner | TuranSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-14 18:17:20 UTC |
| Updated | 2026-06-14 18:17:20 UTC |
| Description | LiamBindle MQTT-C through version 1.1.6 contains a heap-based out-of-bounds read and integer underflow in the mqtt_unpack_publish_response() function in src/mqtt.c that allows a remote unauthenticated attacker controlling an MQTT broker - or able to inject MQTT traffic into an unencrypted session - to crash a subscribed MQTT-C client and potentially disclose adjacent heap memory by sending a single crafted PUBLISH packet. The function validates only that the fixed-header remaining_length is at least 4, then reads the 16-bit topic_name_size field from the broker-controlled packet and advances the parse pointer by that value without verifying that topic_name_size plus the surrounding overhead fits within remaining_length; it subsequently computes application_message_size as remaining_length - topic_name_size - 2 (QoS 0) or - 4 (QoS greater than 0) in unsigned arithmetic, producing an integer underflow that is then passed to memmove(). A PUBLISH packet with topic_name_size = 0xFFFF and remaining_length = 7 advances the parse pointer 65535 bytes past the receive buffer (out-of-bounds read) and causes an application_message_size near 2^32, crashing the process when the resulting memmove() is executed. |
Risk And Classification
Primary CVSS: v4.0 7.8 HIGH from 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:D/RE:X/U:X
Problem Types: CWE-125 | CWE-191 | CWE-125 CWE-125 Out-of-bounds Read | CWE-191 CWE-191 Integer Underflow (Wrap or Wraparound)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | Secondary | 7.8 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/C... |
| 4.0 | CNA | CVSS | 7.8 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/A... |
| 3.1 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | Secondary | 8.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H |
| 3.1 | CNA | CVSS | 8.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
NoneAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:D/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | LiamBindle | MQTT-C | affected 1.1.6 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| cwe.mitre.org/data/definitions/191.html | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | cwe.mitre.org | |
| cwe.mitre.org/data/definitions/125.html | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | cwe.mitre.org | |
| github.com/LiamBindle/MQTT-C/blob/v1.1.6/src/mqtt.c | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | github.com | |
| github.com/LiamBindle/MQTT-C | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Saidakbarxon Maxsudxonov (en)
There are currently no legacy QID mappings associated with this CVE.