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_COILS case, aka VD-1302.
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 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
spanwich/sel4-ics-gateway-demo ★ 0 · Jan 1, 2026
Defensive security demo: seL4 microkernel gateway protecting vulnerable ICS from CVE-2019-14462
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
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