{"id":"CVE-2026-121963","kind":"vulnerability","aliases":["CVE-2026-121963"],"related":[],"title":"FreeRDP: malicious RDP server can crash client via audio channel","description":"FreeRDP before 3.32.2 contains a use-after-free vulnerability in the asynchronous dynamic rdpsnd channel that allows malicious RDP servers to trigger freed callback access by closing the channel with queued audio PDUs. Attackers can send a training PDU then close the channel so the playback thread reads the freed callback in rdpsnd_virtual_channel_write, crashing the client.","summary":"FreeRDP before 3.32.2 has a use-after-free in its asynchronous rdpsnd audio channel. A malicious RDP server can close the channel with queued audio data so the client reads freed memory, which crashes the client.","severity":"high","cvss":8.2,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["freerdp","linux","package","remote-desktop","windows"],"not_affected_if":["freerdp-3.32.2-or-later","only-trusted-rdp-servers"],"how_to_check":"- Check the installed FreeRDP version (for example `xfreerdp --version`) and compare it with the fixed release.\n- Look for FreeRDP builds bundled inside other applications, since those may not show up as a separate package.","fix":"- FreeRDP: upgrade to `3.32.2` or later.","status":"open","published_at":"2026-11-04T16:17:49+00:00","first_seen_at":"2026-11-04T16:28:14+00:00","triaged_at":"2026-11-04T16:28:46+00:00","updated_at":"2026-11-04T16:28:46+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-04T16:28:46Z","model":"claude-haiku-5-5","output":{"fix":"- FreeRDP: upgrade to `3.32.2` or later.","reach":"network","title":"FreeRDP: malicious RDP server can crash client via audio channel","impact":"low","summary":"FreeRDP before 3.32.2 has a use-after-free in its asynchronous rdpsnd audio channel. A malicious RDP server can close the channel with queued audio data so the client reads freed memory, which crashes the client.","audience":"businesses","category":"package","nicknames":[],"who_cares":["freerdp","remote-desktop","linux","windows"],"confidence":0.6,"fix_status":"available","needs_auth":"unknown","worst_case":"Client application crashes when connecting to a malicious server","analyst_note":"","how_to_check":"- Check the installed FreeRDP version (for example `xfreerdp --version`) and compare it with the fixed release.\n- Look for FreeRDP builds bundled inside other applications, since those may not show up as a separate package.","plain_action":"","needs_analyst":false,"not_affected_if":["freerdp-3.32.2-or-later","only-trusted-rdp-servers"],"who_is_affected":"Any client that connects to remote desktop servers using FreeRDP versions before 3.32.2 and the asynchronous dynamic rdpsnd audio channel. The attacker must control the RDP server the client connects to, so exposure comes from connecting to untrusted or compromised servers. Teams that only use FreeRDP against trusted servers face less risk, though the fix is still the upgrade. The sources do not say whether the asynchronous audio channel is enabled by default.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000717,"input_tokens":4210,"output_tokens":592,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-121963':13A,16A '-2026':12A,15A '3.32.2':26B,63C 'access':86C 'allow':78C 'asynchron':35B,73C 'attack':95C 'audio':9A,37B,49B,93C 'callback':85C,112C 'channel':10A,38B,46B,76C,90C,104C,116C 'client':7A,53B,60B,120C 'close':44B,88C,102C 'contain':64C 'crash':6A,58B,118C 'cve':11A,14A 'data':50B 'desktop':22B 'dynam':74C 'free':32B,69C 'freed':55B,84C,111C 'freerdp':1A,17B,24B,61C 'linux':18B 'malici':2A,40B,79C 'memori':56B 'packag':19B 'pdu':100C 'pdus':94C 'playback':107C 'queu':48B,92C 'rdp':3A,41B,80C 'rdpsnd':36B,75C,114C 'read':54B,109C 'remot':21B 'remote-desktop':20B 'send':97C 'server':4A,42B,81C 'thread':108C 'train':99C 'trigger':83C 'use':30B,67C 'use-after-fre':29B,66C 'via':8A 'virtual':115C 'vulner':70C 'window':23B 'write':117C","nicknames":[],"mitigations":[],"who_affected":"Any client that connects to remote desktop servers using FreeRDP versions before 3.32.2 and the asynchronous dynamic rdpsnd audio channel. The attacker must control the RDP server the client connects to, so exposure comes from connecting to untrusted or compromised servers. Teams that only use FreeRDP against trusted servers face less risk, though the fix is still the upgrade. The sources do not say whether the asynchronous audio channel is enabled by default.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["freerdp","high","linux","package","remotedesktop","windows"],"campaign_type":null,"first_public_at":"2026-10-20T17:17:04+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-121963","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121963","severity":null,"published_at":"2026-11-04T16:17:49+00:00","modified_at":"2026-11-04T16:17:49+00:00","first_seen_at":"2026-11-04T16:28:14+00:00","fetched_at":"2026-11-04T16:28:14+00:00","note":null}],"documents":[{"id":68499,"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-cx9c-q4jc-wm6c","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-20T17:17:04+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":68500,"url":"https://www.vulncheck.com/advisories/freerdp-before-3.32.2-use-after-free-via-dynamic-rdpsnd-channel-close","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}