Buffer overflow in Hamlib

CVE-2026-54634

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.004 (38.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-54634: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-54634?
CVE-2026-54634 is a high-severity vulnerability in Hamlib, classified under Out-of-bounds Write. CVSS score: 7.3/10. Published 2026-09-17.
How severe is CVE-2026-54634?
High severity. CVSS v3 base score is 7.3 out of 10.