{"id":"CVE-2026-121400","kind":"vulnerability","aliases":["CVE-2026-121400"],"related":[],"title":"FreeRDP: malicious RD Gateway can pin client CPU with stalled packet","description":"FreeRDP before 3.32.2 contains a denial-of-service vulnerability in rdg_process_control_packet that allows a malicious RD Gateway to exhaust client CPU by sending an incomplete keepalive control packet. Attackers completing the RDG tunnel-open exchange then send an eight-byte header with packetLength 0xFFFF and withhold the body, causing an unbounded no-progress read loop that spins one client thread at full CPU.","summary":"FreeRDP before 3.32.2 mishandles an incomplete keepalive control packet from a Remote Desktop Gateway. A malicious gateway can hold a client thread in an endless read loop that consumes a full CPU core, causing denial of service on the client.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["freerdp","other","rd-gateway","remote-desktop"],"not_affected_if":["freerdp-3.32.2-or-later","no-rd-gateway"],"how_to_check":"- Check the installed FreeRDP version, for example with `xfreerdp /version`.\n- Look for FreeRDP builds below `3.32.2` in packaged apps or bundled libraries.","fix":"- FreeRDP: upgrade to `3.32.2` or later.","status":"open","published_at":"2026-11-03T15:17:28+00:00","first_seen_at":"2026-11-03T15:21:57+00:00","triaged_at":"2026-11-03T15:23:02+00:00","updated_at":"2026-11-03T15:23:02+00:00","category":"other","confidence":0.8,"triage":{"at":"2026-11-03T15:23:02Z","model":"claude-haiku-5-5","output":{"fix":"- FreeRDP: upgrade to `3.32.2` or later.","reach":"network","title":"FreeRDP: malicious RD Gateway can pin client CPU with stalled packet","impact":"low","summary":"FreeRDP before 3.32.2 mishandles an incomplete keepalive control packet from a Remote Desktop Gateway. A malicious gateway can hold a client thread in an endless read loop that consumes a full CPU core, causing denial of service on the client.","audience":"businesses","category":"other","nicknames":[],"who_cares":["freerdp","remote-desktop","rd-gateway"],"confidence":0.8,"fix_status":"available","needs_auth":"unknown","worst_case":"client thread spins at full CPU, causing denial of service","analyst_note":"","how_to_check":"- Check the installed FreeRDP version, for example with `xfreerdp /version`.\n- Look for FreeRDP builds below `3.32.2` in packaged apps or bundled libraries.","plain_action":"","needs_analyst":false,"not_affected_if":["no-rd-gateway","freerdp-3.32.2-or-later"],"who_is_affected":"Client machines running FreeRDP before 3.32.2 that connect through an RD Gateway, where the gateway may be untrusted or attacker-controlled. The sources say the attacker must complete the RDG tunnel-open exchange first, so exposure depends on connecting to a hostile gateway. Servers and clients that never use an RD Gateway are not described as affected.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000703,"input_tokens":4221,"output_tokens":562,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-121400':14A,17A '-2026':13A,16A '0xffff':115C '3.32.2':28B,68C 'allow':82C 'attack':98C 'bodi':119C 'byte':111C 'caus':59B,120C 'client':7A,46B,65B,89C,131C 'complet':99C 'consum':54B 'contain':69C 'control':33B,79C,96C 'core':58B 'cpu':8A,57B,90C,135C 'cve':12A,15A 'denial':60B,72C 'denial-of-servic':71C 'desktop':25B,38B 'eight':110C 'eight-byt':109C 'endless':50B 'exchang':105C 'exhaust':88C 'freerdp':1A,18B,26B,66C 'full':56B,134C 'gateway':4A,22B,39B,42B,86C 'header':112C 'hold':44B 'incomplet':31B,94C 'keepal':32B,95C 'loop':52B,127C 'malici':2A,41B,84C 'mishandl':29B 'no-progress':123C 'one':130C 'open':104C 'packet':11A,34B,80C,97C 'packetlength':114C 'pin':6A 'process':78C 'progress':125C 'rd':3A,21B,85C 'rd-gateway':20B 'rdg':77C,101C 'read':51B,126C 'remot':24B,37B 'remote-desktop':23B 'send':92C,107C 'servic':62B,74C 'spin':129C 'stall':10A 'thread':47B,132C 'tunnel':103C 'tunnel-open':102C 'unbound':122C 'vulner':75C 'withhold':117C","nicknames":[],"mitigations":[],"who_affected":"Client machines running FreeRDP before 3.32.2 that connect through an RD Gateway, where the gateway may be untrusted or attacker-controlled. The sources say the attacker must complete the RDG tunnel-open exchange first, so exposure depends on connecting to a hostile gateway. Servers and clients that never use an RD Gateway are not described as affected.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["freerdp","high","other","rdgateway","remotedesktop"],"first_public_at":"2026-10-19T12:11:34+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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-2026-121400","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121400","severity":null,"published_at":"2026-11-03T15:17:28+00:00","modified_at":"2026-11-03T15:17:28+00:00","first_seen_at":"2026-11-03T15:21:57+00:00","fetched_at":"2026-11-03T15:21:57+00:00","note":null}],"documents":[{"id":58323,"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x4x6-2hrm-hvq9","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-19T12:11:34+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":58324,"url":"https://www.vulncheck.com/advisories/freerdp-before-3.32.2-cpu-exhaustion-via-rdg-control-packet","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"}