CVE-2026-54634 Hamlib: rigctld `send_raw` Stack Out-of-Bounds Write and Uninitialized Memory Disclosure
Remote attackers can crash the rigctld daemon or leak stack memory via a malformed send_raw command in Hamlib.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54634?
CVE-2026-54634 is a high-severity memory corruption vulnerability in Hamlib, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Hamlib is a ham radio control library for radios, rotators, and amplifiers. Prior to 4.7.2, the unauthenticated rigctld send_raw command on TCP port 4532 reaches rigctl_send_raw() in tests/rigctl_parse.c, which writes a NUL byte at buf[buf_len + 1] outside its 200-byte stack buffer, and rig_send_raw() in src/rig.c, which copies reply_len - 1 bytes instead of the actual nbytes received. A remote client can send the CR terminator with a short payload to trigger both flaws in one command under the default no-password configuration. The out-of-bounds write can crash the daemon or corrupt adjacent stack memory, while the oversized copy can return up to 198 bytes of uninitialized stack data to the client. This issue is fixed in version 4.7.2.
Which versions are affected by CVE-2026-54634?
Linux distribution packages (2)
hamlib openSUSE:Leap 16.0 | All versions | 4.7.2-bp160.1.1 |
hamlib openSUSE:Tumbleweed | All versions | 4.7.2-1.1 |
How do I fix CVE-2026-54634?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-54634 being exploited?
There is no known exploitation of CVE-2026-54634 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-54634, GHSA-gpcq-c37x-pr46, MGASA-2026-0475, UBUNTU-CVE-2026-54634, openSUSE-SU-2026:11089-1, openSUSE-SU-2026:21155-1.