{"id":"CVE-2026-121399","kind":"vulnerability","aliases":["CVE-2026-121399"],"related":[],"title":"FreeRDP: malicious RD Gateway forces 2 GiB allocation, crashing clients","description":"FreeRDP before 3.32.2 contains a memory allocation vulnerability in rdg_receive_packet that allows a malicious RD Gateway to force a 2 GiB client allocation before tunnel authentication. Attackers can send an eight-byte RDG header declaring packet length 0x7FFFFFFF to trigger pre-authentication memory exhaustion and denial of service.","summary":"FreeRDP before 3.32.2 mishandles an RD Gateway packet length field in rdg_receive_packet, so a malicious gateway can make the client allocate 2 GiB before tunnel authentication. An attacker gets pre-authentication memory exhaustion and denial of service against the client.","severity":"medium","cvss":5.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["freerdp","linux","package","rd-gateway","remote-desktop","windows"],"not_affected_if":["direct-rdp-only","no-rd-gateway"],"how_to_check":"- Check the installed FreeRDP version against the range in the advisory: `xfreerdp /version` or the package manager's version query\n- Look for FreeRDP builds used as RD Gateway clients on workstations and servers that connect through a gateway","fix":"- FreeRDP: move 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":"2026-11-03T15:24:33+00:00","updated_at":"2026-11-03T15:24:33+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-03T15:24:33Z","model":"claude-haiku-5-5","output":{"fix":"- FreeRDP: move to `3.32.2` or later","reach":"network","title":"FreeRDP: malicious RD Gateway forces 2 GiB allocation, crashing clients","impact":"low","summary":"FreeRDP before 3.32.2 mishandles an RD Gateway packet length field in rdg_receive_packet, so a malicious gateway can make the client allocate 2 GiB before tunnel authentication. An attacker gets pre-authentication memory exhaustion and denial of service against the client.","audience":"developers","category":"package","nicknames":[],"who_cares":["freerdp","rd-gateway","remote-desktop","linux","windows"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"Client process crashes or exhausts memory, causing denial of service","analyst_note":"","how_to_check":"- Check the installed FreeRDP version against the range in the advisory: `xfreerdp /version` or the package manager's version query\n- Look for FreeRDP builds used as RD Gateway clients on workstations and servers that connect through a gateway","plain_action":"","needs_analyst":false,"not_affected_if":["no-rd-gateway","direct-rdp-only"],"who_is_affected":"Systems running a FreeRDP client that connects through an RD Gateway, including embedded or bundled copies in other products. Exposure requires connecting to a gateway an attacker controls or can impersonate, since the flaw is triggered before tunnel authentication. Direct RDP connections without a gateway are not described as affected.","user_interaction":"unknown","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000708,"input_tokens":4202,"output_tokens":575,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-121399':13A,16A '-2026':12A,15A '0x7fffffff':110C '2':6A,50B,91C '3.32.2':29B,72C 'alloc':8A,49B,76C,94C 'allow':83C 'attack':56B,98C 'authent':54B,60B,97C,115C 'byte':104C 'client':10A,48B,69B,93C 'contain':73C 'crash':9A 'cve':11A,14A 'declar':107C 'denial':64B,119C 'desktop':25B 'eight':103C 'eight-byt':102C 'exhaust':62B,117C 'field':36B 'forc':5A,89C 'freerdp':1A,17B,27B,70C 'gateway':4A,22B,33B,44B,87C 'get':57B 'gib':7A,51B,92C 'header':106C 'length':35B,109C 'linux':18B 'make':46B 'malici':2A,43B,85C 'memori':61B,75C,116C 'mishandl':30B 'packag':19B 'packet':34B,40B,81C,108C 'pre':59B,114C 'pre-authent':58B,113C 'rd':3A,21B,32B,86C 'rd-gateway':20B 'rdg':38B,79C,105C 'receiv':39B,80C 'remot':24B 'remote-desktop':23B 'send':100C 'servic':66B,121C 'trigger':112C 'tunnel':53B,96C 'vulner':77C 'window':26B","nicknames":[],"mitigations":[],"who_affected":"Systems running a FreeRDP client that connects through an RD Gateway, including embedded or bundled copies in other products. Exposure requires connecting to a gateway an attacker controls or can impersonate, since the flaw is triggered before tunnel authentication. Direct RDP connections without a gateway are not described as affected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["freerdp","linux","medium","package","rdgateway","remotedesktop","windows"],"first_public_at":"2026-10-19T12:11:16+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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-2026-121399","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121399","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":58321,"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4vh4-3pc3-32p7","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-19T12:11:16+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":58322,"url":"https://www.vulncheck.com/advisories/freerdp-before-3.32.2-memory-exhaustion-via-rd-gateway-packet-length","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"}