Description
In Mosquitto before 1.4.12, pattern based ACLs can be bypassed by clients that set their username/client id to '#' or '+'. This allows locally or remotely connected clients to access MQTT topics that they do have the rights to. The same issue may be present in third party authentication/access control plugins for Mosquitto.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Eclipse Foundation | Mosquitto | 0.15 to 1.4.11 inclusive | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | mosquitto | 1.4.10-3 | — |
| Debian 13 | mosquitto | 1.4.10-3 | — |
| Debian 12 | mosquitto | 1.4.10-3 | — |
| Debian 8 | mosquitto | 1.3.4-2+deb8u1 | DSA-3865-1 |
| Debian 7 | mosquitto | 0.15-2+deb7u1 | DLA-961-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | mosquitto | 1.4.8-1ubuntu0.16.04.1 | — |
| Ubuntu 14.04 LTS | mosquitto | 0.15-2ubuntu1.1 | — |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.23 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.22 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.21 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.20 | mosquitto | 1.4.12-r0 | — |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.18 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.17 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.16 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.15 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.14 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.13 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.12 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.11 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.10 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.9 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.8 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.7 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.6 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.5 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.4 | mosquitto | 1.4.12-r0 | — |
| Alpine v3.3 | mosquitto | 1.4.12-r0 | — |
Advisories 2
- DLA-961-1 mosquitto - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3865-1 mosquitto - security update Debian Security (DSA / DLA) · Mar 9, 2026