CVE-2026-18649

Summary

A flaw was found in the GStreamer gst-plugins-good package. The rtph264depay and rtph265depay RTP depayloader elements do not enforce a maximum size limit on the reassembly buffer used during fragmented RTP packet processing. A remote, unauthenticated attacker can send a continuous stream of RTP fragments without ever transmitting an end-of-fragment marker, causing the reassembly buffer to grow without bound until process memory is exhausted. This results in a denial of service through process termination.

Affected Software

VendorProductVersion RangeStatus

Weaknesses

  • CWE-770: Allocation of Resources Without Limits or Throttling

Workarounds

The following mitigations can reduce risk before a patch is available:

  1. Use SRTP or DTLS-SRTP: Deploy the srtpdec element in the pipeline before the depayloader. SRTP provides per-packet authentication and will reject unauthenticated fragments before they reach rtph264depay/rtph265depay, completely preventing exploitation.

  2. Network-level restriction: Use firewall rules (iptables/nftables) to restrict which sources can send RTP traffic to the GStreamer process. Allow RTP only from trusted, authenticated peers.

  3. Build-time exclusion: Disable the entire RTP plugin by configuring with "-Drtp=disabled" in meson build options. This removes all RTP functionality including the vulnerable depayloaders.

  4. Runtime element exclusion: Prevent the affected elements from being auto-plugged by setting GST_PLUGIN_FEATURE_RANK=rtph264depay:0,rtph265depay:0. This prevents automatic selection but not explicit pipeline construction.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References