Description
A Buffer Overflow issue was discovered in Kamailio before 4.4.7, 5.0.x before 5.0.6, and 5.1.x before 5.1.2. A specially crafted REGISTER message with a malformed branch or From tag triggers an off-by-one heap-based buffer overflow in the tmx_check_pretran function in modules/tmx/tmx_pretran.c.
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 | kamailio | 5.1.2-1 | — |
| Debian 13 | kamailio | 5.1.2-1 | — |
| Debian 12 | kamailio | 5.1.2-1 | — |
| Debian 9 | kamailio | 4.4.4-2+deb9u1 | DSA-4148-1 |
| Debian 8 | kamailio | 4.2.0-2+deb8u3 | DSA-4148-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | kamailio | 4.3.4-1.1ubuntu2.1 | USN-4240-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.6 | kamailio | 5.0.2-r2 | — |
| Alpine v3.5 | kamailio | 4.4.5-r1 | — |
| Alpine v3.4 | kamailio | 4.4.0-r2 | — |
Advisories 2
- DSA-4148-1 kamailio - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-4240-1 kamailio vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026