Description
An issue was discovered in libmodbus before 3.0.7 and 3.1.x before 3.1.5. There is an out-of-bounds read for the MODBUS_FC_WRITE_MULTIPLE_REGISTERS case, aka VD-1301.
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 | libmodbus | 3.1.6-1 | — |
| Debian 13 | libmodbus | 3.1.6-1 | — |
| Debian 12 | libmodbus | 3.1.6-1 | — |
| Debian 9 | libmodbus | 3.0.6-2+deb9u1 | DLA-2825-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libmodbus | 3.0.6-2+deb9u1build0.18.04.1 | USN-5173-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | libmodbus | 3.0.6-1ubuntu0.1~esm1 | USN-5173-2 |
| Ubuntu Pro 14.04 LTS | libmodbus | 3.0.5-1ubuntu0.1~esm1 | USN-5173-2 |
Advisories 3
- USN-5173-2 libmodbus vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-5173-1 libmodbus vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-2825-1 libmodbus - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- https://github.com/stephane/libmodbus/commit/5ccdf5ef79d742640355d1132fa9e2abc7fbaefc
- https://libmodbus.org/2019/stable-and-development-releases/
- FEDORA-2019-4942e01cdc vendor-advisory
- FEDORA-2019-355f6e10c1 vendor-advisory
- [debian-lts-announce] 20211122 [SECURITY] [DLA 2825-1] libmodbus security update mailing-list