{"id":"CVE-2026-121394","kind":"vulnerability","aliases":["CVE-2026-121394"],"related":[],"title":"FreeRDP: malicious RDP server crashes clients via RemoteFX decoder assertion","description":"FreeRDP from 3.11.0 before 3.32.2 contains an assertion failure in the RemoteFX RLGR decoder that allows malicious servers to terminate clients. Attackers controlling an RDP server can send a RemoteFX tileset with RLGR code 32767, triggering a signed narrowing assertion in rfx_rlgr_decode and crashing the client.","summary":"FreeRDP from 3.11.0 before 3.32.2 has an assertion failure in its RemoteFX RLGR decoder. A malicious RDP server can send a crafted RemoteFX tileset that makes the client crash.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["freerdp","linux","remote-desktop","runtime","windows"],"not_affected_if":["older-or-newer-version","trusted-servers-only"],"how_to_check":"- Check the installed FreeRDP version with `xfreerdp --version` or the package manager, and compare against the fixed range.\n- Confirm whether the client connects to servers you do not control.","fix":"- FreeRDP `3.32.2` and later, per the NVD description (affected range 3.11.0 before 3.32.2).","status":"open","published_at":"2026-11-03T15:17:27+00:00","first_seen_at":"2026-11-03T15:21:57+00:00","triaged_at":"2026-11-03T15:23:05+00:00","updated_at":"2026-11-03T15:23:05+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-11-03T15:23:05Z","model":"claude-haiku-5-5","output":{"fix":"- FreeRDP `3.32.2` and later, per the NVD description (affected range 3.11.0 before 3.32.2).","reach":"network","title":"FreeRDP: malicious RDP server crashes clients via RemoteFX decoder assertion","impact":"low","summary":"FreeRDP from 3.11.0 before 3.32.2 has an assertion failure in its RemoteFX RLGR decoder. A malicious RDP server can send a crafted RemoteFX tileset that makes the client crash.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["freerdp","remote-desktop","linux","windows"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Client application crashes when connected to a malicious server","analyst_note":"","how_to_check":"- Check the installed FreeRDP version with `xfreerdp --version` or the package manager, and compare against the fixed range.\n- Confirm whether the client connects to servers you do not control.","plain_action":"","needs_analyst":false,"not_affected_if":["older-or-newer-version","trusted-servers-only"],"who_is_affected":"Teams whose users connect to RDP servers they do not fully trust, such as remote desktop clients used to reach third-party or public hosts. Exposure needs a malicious server to be on the other end of the connection; servers you run yourself are not the threat described.","user_interaction":"unknown","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000681,"input_tokens":4204,"output_tokens":522,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-121394':13A,16A '-2026':12A,15A '3.11.0':26B,55C '3.32.2':28B,57C '32767':87C 'allow':68C 'assert':10A,31B,60C,92C 'attack':74C 'client':6A,51B,73C,100C 'code':86C 'contain':58C 'control':75C 'craft':45B 'crash':5A,52B,98C 'cve':11A,14A 'decod':9A,37B,66C,96C 'desktop':21B 'failur':32B,61C 'freerdp':1A,17B,24B,53C 'linux':18B 'make':49B 'malici':2A,39B,69C 'narrow':91C 'rdp':3A,40B,77C 'remot':20B 'remote-desktop':19B 'remotefx':8A,35B,46B,64C,82C 'rfx':94C 'rlgr':36B,65C,85C,95C 'runtim':22B 'send':43B,80C 'server':4A,41B,70C,78C 'sign':90C 'termin':72C 'tileset':47B,83C 'trigger':88C 'via':7A 'window':23B","nicknames":[],"mitigations":[],"who_affected":"Teams whose users connect to RDP servers they do not fully trust, such as remote desktop clients used to reach third-party or public hosts. Exposure needs a malicious server to be on the other end of the connection; servers you run yourself are not the threat described.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["freerdp","high","linux","remotedesktop","runtime","windows"],"first_public_at":"2026-10-19T12:04:43+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-2026-121394","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121394","severity":null,"published_at":"2026-11-03T15:17:27+00:00","modified_at":"2026-11-03T15:17:27+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":58311,"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5j39-x36c-x9pm","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-19T12:04:43+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":58312,"url":"https://www.vulncheck.com/advisories/freerdp-before-3.32.2-denial-of-service-via-remotefx-rlgr-decoder","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"}