GNU Gatekeeper before 5.16 Out-of-Bounds Read in H.460.24 RTCP Probe Handler

Advisories

GNU Gatekeeper before 5.16 Out-of-Bounds Read in H.460.24 RTCP Probe Handler

Severity: medium
Date: 11/3/2026
Affecting: gnugk >= 0, < 5.16
CVE: CVE-2026-121626
CWE: CWE-125 Out-of-bounds Read
CVSS: 6.3
CVSS V4 Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References: Patch Commit
gnugk v5_16 Release Notes
https://github.com/willamowius/gnugk/blob/v5_15/GkClient.cxx#L963-L990
https://github.com/willamowius/gnugk
Credit: Tristan Madani (Talence Security), Jan Willamowius
Description: GNU Gatekeeper (gnugk) before 5.16 contains an out-of-bounds read vulnerability in H46024Socket::ReceivedProbePacket() that allows remote attackers to cause a heap over-read by sending short probe packets. Attackers can send a short application-defined RTCP packet to the media port during H.460.24 probing to read past the heap allocation and possibly crash the gatekeeper.

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