---
id: CVE-2026-121625
title: GNU Gatekeeper before 5.16 Out-of-Bounds Read via RTCP SDES Parsing
summary: >-
  GNU Gatekeeper (gnugk) before 5.16 contains an out-of-bounds read
  vulnerability in ParseRTCP() in ProxyChannel.cxx that allows remote RTP peers
  to read heap memory past received packets. Attackers can send RTCP SDES items
  lacking a NUL b…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-125
vendor: willamowius
product: gnugk
affected:
  - gnugk < 5.16
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-03T17:24:07.685551Z'
published: '2026-11-03'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T17:24:49.403Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-121625'
references:
  - url: >-
      https://github.com/willamowius/gnugk/commit/e8939d03b0b2ef46e356f3144a6ee14f2920b777
    label: Patch Commit
  - url: 'https://github.com/willamowius/gnugk/releases/tag/v5_16'
    label: gnugk v5_16 Release Notes
  - url: >-
      https://github.com/willamowius/gnugk/blob/v5_15/ProxyChannel.cxx#L14867-L14895
  - url: 'https://github.com/willamowius/gnugk'
  - url: >-
      https://www.vulncheck.com/advisories/gnu-gatekeeper-before-5.16-out-of-bounds-read-via-rtcp-sdes-parsing
    label: >-
      VulnCheck Advisory: GNU Gatekeeper before 5.16 Out-of-Bounds Read via RTCP
      SDES Parsing
tags:
  - cve.org
epss: 0.00362
epssPercentile: 0.30167
ingestedAt: '2026-11-05T20:33:06.311Z'
---

## Overview

GNU Gatekeeper (gnugk) before 5.16 contains an out-of-bounds read vulnerability in ParseRTCP() in ProxyChannel.cxx that allows remote RTP peers to read heap memory past received packets. Attackers can send RTCP SDES items lacking a NUL byte to the media proxy port during proxied H.323 calls with EnableRTCPStats enabled, crashing the gatekeeper.

## Affected

- `gnugk < 5.16`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.