{"id":"CVE-2026-111074","kind":"vulnerability","aliases":["CVE-2026-111074"],"related":[],"title":"Eclipse OpenJ9: crafted TCP connections halt JITServer compilation without login","description":"In Eclipse OpenJ9 versions prior to 0.63.0, the JITServer component is vulnerable to a pre-authentication remote denial of service. When processing the initial 4-byte length field of an incoming TCP connection, an integer overflow in `MessageBuffer::computeRequiredCapacity()` causes the receiving compilation worker thread to enter an infinite loop consuming ~100% CPU. An unauthenticated remote attacker can exploit this by opening a small number of crafted TCP connections to exhaust the entire worker thread pool, silently halting compilation services for all connected client JVMs.","summary":"Eclipse OpenJ9 before 0.63.0 has an integer overflow in the JITServer length-field handling, so an unauthenticated remote client can send a few crafted TCP connections. The compilation worker threads then spin at about 100% CPU, stopping compilation for every connected client JVM.","severity":"high","cvss":8.7,"epss":0.00421,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["java","jitserver","openj9","runtime","self-hosted"],"not_affected_if":["default-config","no-jitserver"],"how_to_check":"Check whether JITServer mode is in use: look for -XX:+JITServer or -XX:JITServerAddress flags in JVM startup options, and check the OpenJ9 version with java -version.","fix":"Upgrade Eclipse OpenJ9 to 0.63.0 or later.\nUntil then, restrict network access to the JITServer port to trusted client hosts.","status":"open","published_at":"2026-10-21T08:16:42+00:00","first_seen_at":"2026-10-23T21:57:28+00:00","triaged_at":"2026-10-23T22:36:56+00:00","updated_at":"2026-10-24T13:15:54+00:00","category":"runtime","confidence":0.8,"triage":{"at":"2026-10-23T22:36:56Z","model":"claude-haiku-5-5","output":{"fix":"Upgrade Eclipse OpenJ9 to 0.63.0 or later.\nUntil then, restrict network access to the JITServer port to trusted client hosts.","reach":"network","title":"Eclipse OpenJ9: crafted TCP connections halt JITServer compilation without login","impact":"medium","summary":"Eclipse OpenJ9 before 0.63.0 has an integer overflow in the JITServer length-field handling, so an unauthenticated remote client can send a few crafted TCP connections. The compilation worker threads then spin at about 100% CPU, stopping compilation for every connected client JVM.","category":"runtime","who_cares":["java","openj9","jitserver","self-hosted"],"confidence":0.8,"needs_auth":"no","worst_case":"unauthenticated remote attacker halts JIT compilation service entirely","analyst_note":"","how_to_check":"Check whether JITServer mode is in use: look for -XX:+JITServer or -XX:JITServerAddress flags in JVM startup options, and check the OpenJ9 version with java -version.","needs_analyst":false,"not_affected_if":["default-config","no-jitserver"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000522,"input_tokens":3023,"output_tokens":439,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-111074':13A,16A '-2026':12A,15A '0.63.0':27B,74C '100':59B,120C '4':93C 'attack':125C 'authent':84C 'byte':94C 'caus':108C 'client':43B,66B,152C 'compil':8A,52B,62B,111C,147C 'compon':77C 'computerequiredcapac':107C 'connect':5A,50B,65B,101C,137C,151C 'consum':119C 'cpu':60B,121C 'craft':3A,48B,135C 'cve':11A,14A 'denial':86C 'eclips':1A,24B,69C 'enter':115C 'entir':141C 'everi':64B 'exhaust':139C 'exploit':127C 'field':37B,96C 'halt':6A,146C 'handl':38B 'host':23B 'incom':99C 'infinit':117C 'initi':92C 'integ':30B,103C 'java':17B 'jitserv':7A,18B,34B,76C 'jvm':67B 'jvms':153C 'length':36B,95C 'length-field':35B 'login':10A 'loop':118C 'messagebuff':106C 'number':133C 'open':130C 'openj9':2A,19B,25B,70C 'overflow':31B,104C 'pool':144C 'pre':83C 'pre-authent':82C 'prior':72C 'process':90C 'receiv':110C 'remot':42B,85C,124C 'runtim':20B 'self':22B 'self-host':21B 'send':45B 'servic':88C,148C 'silent':145C 'small':132C 'spin':56B 'stop':61B 'tcp':4A,49B,100C,136C 'thread':54B,113C,143C 'unauthent':41B,123C 'version':71C 'vulner':79C 'without':9A 'worker':53B,112C,142C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-21T08:16:42+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/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":"emo@eclipse.org","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-111074","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-111074","severity":null,"published_at":"2026-10-21T08:16:42+00:00","modified_at":"2026-10-22T17:21:57+00:00","first_seen_at":"2026-10-23T21:57:28+00:00","fetched_at":"2026-10-23T22:29:01+00:00","note":null},{"source":"epss","external_id":"CVE-2026-111074","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-111074","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T13:15:54+00:00","fetched_at":"2026-10-24T13:15:54+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}