Description
In Eclipse Mosquitto 1.5.0 to 1.6.5 inclusive, if a malicious MQTT client sends a SUBSCRIBE packet containing a topic that consists of approximately 65400 or more '/' characters, i.e. the topic hierarchy separator, then a stack overflow will occur.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| The Eclipse Foundation | Eclipse Mosquitto | 1.5.0 to 1.6.5 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 | 1.6.6-1 | — |
| Debian 13 | mosquitto | 1.6.6-1 | — |
| Debian 12 | mosquitto | 1.6.6-1 | — |
| Debian 10 | mosquitto | 1.5.7-1+deb10u1 | DSA-4570-1 |
| Debian 8 | mosquitto | 1.3.4-2+deb8u4 | DLA-1972-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | mosquitto | 1.5.7-bp151.3.3.1 | openSUSE-SU-2019:2247-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | mosquitto | 1.5.7-lp151.2.3.1 | openSUSE-SU-2019:2206-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.23 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.22 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.21 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.20 | mosquitto | 1.6.7-r0 | — |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.18 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.17 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.16 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.15 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.14 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.13 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.12 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.11 | mosquitto | 1.6.7-r0 | — |
| Alpine v3.10 | mosquitto | 1.6.3-r1 | — |
| Alpine v3.9 | mosquitto | 1.5.6-r1 | — |
Advisories 4
- DSA-4570-1 mosquitto - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1972-1 mosquitto - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2019:2206-1 Security update for mosquitto SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:2247-1 Security update for mosquitto SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=551160
- USN-4137-1 vendor-advisory
- openSUSE-SU-2019:2206 vendor-advisory
- openSUSE-SU-2019:2247 vendor-advisory
- FEDORA-2019-4c69fb4cd7 vendor-advisory
- FEDORA-2019-8b83c261dd vendor-advisory
- FEDORA-2019-d99e2329cb vendor-advisory
- [debian-lts-announce] 20191026 [SECURITY] [DLA 1972-1] mosquitto security update mailing-list
- DSA-4570 vendor-advisory
- 20191118 [SECURITY] [DSA 4570-1] mosquitto security update mailing-list