{"id":"CVE-2026-82440","kind":"vulnerability","aliases":["CVE-2026-82440"],"related":[],"title":"Apache Storm: Nimbus instantiates any class named in topology scheduler strategy","description":"Description\n\nNimbus instantiates the class named by a topology's `topology.scheduler.strategy` when scheduling it. The\nallowlist intended to constrain that choice, `nimbus.scheduler.strategy.class.whitelist`, was treated as\n\"allow any class\" when unset, and it had no entry in the shipped `defaults.yaml`, so unset was the shipped\nstate. An authenticated submitter could therefore cause Nimbus to instantiate any class on the Nimbus\nclasspath that has a no-argument constructor.\n\nStorm's own production artifacts contain classes with side effects suitable for this: instantiating\n`org.apache.storm.testing.InProcessZookeeper` starts a ZooKeeper server with its own threads and sockets\nand nothing closes it, and `org.apache.storm.LocalCluster` behaves similarly. Repeated submissions\ntherefore consume threads, sockets and memory in the most privileged daemon in the cluster.\n\nMitigation\n\nUpgrade to 3.1.0, where an unset allowlist means the strategies shipped with Storm rather than any class.\n\nNote that this is a behaviour change: a cluster running an out-of-tree scheduler strategy without an\nexplicit allowlist will have those topologies refused until the class is added to\n`nimbus.scheduler.strategy.class.whitelist`. The rejection message names the refused class and the\nconfiguration key.\n\nUsers who cannot upgrade immediately should set `nimbus.scheduler.strategy.class.whitelist` explicitly to\nthe strategies they intend to permit.","summary":"When the scheduler strategy allowlist is unset, Nimbus instantiates any no-argument class on its classpath when a topology is scheduled. An authenticated submitter can use this to start side-effecting classes such as InProcessZookeeper and exhaust threads, sockets and memory in the Nimbus daemon.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["apache-storm","nimbus","package","self-hosted"],"not_affected_if":["auth-required","explicit-whitelist"],"how_to_check":"- Check the Storm version in use with `storm version`; affected versions are those before `3.1.0`.\n- Check whether `nimbus.scheduler.strategy.class.whitelist` is set in `storm.yaml` or the Nimbus configuration; if it is unset, the cluster is in the shipped state the advisory describes.","fix":"- Apache Storm: upgrade to `3.1.0`, where an unset allowlist means the strategies shipped with Storm.\n- Until upgraded: set `nimbus.scheduler.strategy.class.whitelist` explicitly to the strategies intended to be permitted.","status":"open","published_at":"2026-11-09T10:17:11+00:00","first_seen_at":"2026-11-09T10:25:49+00:00","triaged_at":"2026-11-09T10:26:35+00:00","updated_at":"2026-11-09T10:26:35+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-11-09T10:26:35Z","model":"claude-haiku-5-5","output":{"fix":"- Apache Storm: upgrade to `3.1.0`, where an unset allowlist means the strategies shipped with Storm.\n- Until upgraded: set `nimbus.scheduler.strategy.class.whitelist` explicitly to the strategies intended to be permitted.","reach":"network","title":"Apache Storm: Nimbus instantiates any class named in topology scheduler strategy","impact":"medium","summary":"When the scheduler strategy allowlist is unset, Nimbus instantiates any no-argument class on its classpath when a topology is scheduled. An authenticated submitter can use this to start side-effecting classes such as InProcessZookeeper and exhaust threads, sockets and memory in the Nimbus daemon.","audience":"businesses","category":"package","nicknames":[],"who_cares":["apache-storm","nimbus","self-hosted"],"confidence":0.8,"fix_status":"available","needs_auth":"yes","worst_case":"Repeated submissions exhaust threads, sockets and memory in Nimbus","analyst_note":"","how_to_check":"- Check the Storm version in use with `storm version`; affected versions are those before `3.1.0`.\n- Check whether `nimbus.scheduler.strategy.class.whitelist` is set in `storm.yaml` or the Nimbus configuration; if it is unset, the cluster is in the shipped state the advisory describes.\n- unknown for the exact affected version range beyond the mitigation text.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["auth-required","explicit-whitelist"],"who_is_affected":"Clusters running Apache Storm Nimbus where the scheduler strategy allowlist is not set, so any class on the classpath can be instantiated when a topology is submitted. Only authenticated submitters can trigger it. Clusters with an explicit allowlist, or those that cannot submit topologies, are not exposed in the same way.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000854,"input_tokens":4961,"output_tokens":716,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-82440':14A,17A '3.1.0':192C 'add':237C 'allow':98C 'allowlist':30B,88C,196C,227C 'apach':1A,19B 'apache-storm':18B 'argument':38B,138C 'artifact':144C 'authent':49B,119C 'behav':171C 'behaviour':212C 'cannot':253C 'caus':123C 'chang':213C 'choic':93C 'class':6A,39B,59B,77C,100C,128C,146C,206C,235C,246C 'classpath':42B,132C 'close':167C 'cluster':188C,215C 'configur':249C 'constrain':91C 'constructor':139C 'consum':176C 'contain':145C 'could':121C 'cve':12A,15A 'daemon':72B,185C 'defaults.yaml':111C 'descript':73C 'effect':58B,149C 'entri':107C 'exhaust':64B 'explicit':226C,259C 'host':25B 'immedi':255C 'inprocesszookeep':62B 'instanti':4A,34B,75C,126C,153C 'intend':89C,264C 'key':250C 'mean':197C 'memori':68B,180C 'messag':242C 'mitig':189C 'name':7A,78C,243C 'nimbus':3A,21B,33B,71B,74C,124C,131C 'nimbus.scheduler.strategy.class.whitelist':94C,239C,258C 'no-argu':36B,136C 'note':207C 'noth':166C 'org.apache.storm.localcluster':170C 'org.apache.storm.testing.inprocesszookeeper':154C 'out-of-tre':218C 'packag':22B 'permit':266C 'privileg':184C 'product':143C 'rather':203C 'refus':232C,245C 'reject':241C 'repeat':173C 'run':216C 'schedul':10A,28B,47B,85C,222C 'self':24B 'self-host':23B 'server':158C 'set':257C 'ship':110C,116C,200C 'side':57B,148C 'side-effect':56B 'similar':172C 'socket':66B,164C,178C 'start':55B,155C 'state':117C 'storm':2A,20B,140C,202C 'strategi':11A,29B,199C,223C,262C 'submiss':174C 'submitt':50B,120C 'suitabl':150C 'therefor':122C,175C 'thread':65B,162C,177C 'topolog':9A,45B,81C,231C 'topology.scheduler.strategy':83C 'treat':96C 'tree':221C 'unset':32B,102C,113C,195C 'upgrad':190C,254C 'use':52B 'user':251C 'without':224C 'zookeep':157C","nicknames":[],"mitigations":[],"who_affected":"Clusters running Apache Storm Nimbus where the scheduler strategy allowlist is not set, so any class on the classpath can be instantiated when a topology is submitted. Only authenticated submitters can trigger it. Clusters with an explicit allowlist, or those that cannot submit topologies, are not exposed in the same way.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["apachestorm","nimbus","package","selfhosted","unknown"],"campaign_type":null,"search_a":"'-2026':13A,16A '-82440':14A,17A 'apach':1A 'class':6A 'cve':12A,15A 'instanti':4A 'name':7A 'nimbus':3A 'schedul':10A 'storm':2A 'strategi':11A 'topolog':9A","search_b":"'allowlist':30B 'apach':19B 'apache-storm':18B 'argument':38B 'authent':49B 'class':39B,59B 'classpath':42B 'daemon':72B 'effect':58B 'exhaust':64B 'host':25B 'inprocesszookeep':62B 'instanti':34B 'memori':68B 'nimbus':21B,33B,71B 'no-argu':36B 'packag':22B 'schedul':28B,47B 'self':24B 'self-host':23B 'side':57B 'side-effect':56B 'socket':66B 'start':55B 'storm':20B 'strategi':29B 'submitt':50B 'thread':65B 'topolog':45B 'unset':32B 'use':52B","search_c":"'3.1.0':192C 'add':237C 'allow':98C 'allowlist':88C,196C,227C 'argument':138C 'artifact':144C 'authent':119C 'behav':171C 'behaviour':212C 'cannot':253C 'caus':123C 'chang':213C 'choic':93C 'class':77C,100C,128C,146C,206C,235C,246C 'classpath':132C 'close':167C 'cluster':188C,215C 'configur':249C 'constrain':91C 'constructor':139C 'consum':176C 'contain':145C 'could':121C 'daemon':185C 'defaults.yaml':111C 'descript':73C 'effect':149C 'entri':107C 'explicit':226C,259C 'immedi':255C 'instanti':75C,126C,153C 'intend':89C,264C 'key':250C 'mean':197C 'memori':180C 'messag':242C 'mitig':189C 'name':78C,243C 'nimbus':74C,124C,131C 'nimbus.scheduler.strategy.class.whitelist':94C,239C,258C 'no-argu':136C 'note':207C 'noth':166C 'org.apache.storm.localcluster':170C 'org.apache.storm.testing.inprocesszookeeper':154C 'out-of-tre':218C 'permit':266C 'privileg':184C 'product':143C 'rather':203C 'refus':232C,245C 'reject':241C 'repeat':173C 'run':216C 'schedul':85C,222C 'server':158C 'set':257C 'ship':110C,116C,200C 'side':148C 'similar':172C 'socket':164C,178C 'start':155C 'state':117C 'storm':140C,202C 'strategi':199C,223C,262C 'submiss':174C 'submitt':120C 'suitabl':150C 'therefor':122C,175C 'thread':162C,177C 'topolog':81C,231C 'topology.scheduler.strategy':83C 'treat':96C 'tree':221C 'unset':102C,113C,195C 'upgrad':190C,254C 'user':251C 'without':224C 'zookeep':157C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-09T10:17:11+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-82440","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82440","severity":null,"published_at":"2026-11-09T10:17:11+00:00","modified_at":"2026-11-09T10:17:11+00:00","first_seen_at":"2026-11-09T10:25:49+00:00","fetched_at":"2026-11-09T10:25:49+00:00","note":null}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}