{"id":"CVE-2026-105933","kind":"vulnerability","aliases":["CVE-2026-105933"],"related":[],"title":"Apache Pulsar: failed topic load silently disables required message encryption","description":"Apache Pulsar allows an administrator to require end-to-end message encryption for all topics in a namespace by setting the encryption_required namespace policy. When this policy is set, the broker rejects messages that are published without encryption.\n\nWhen the broker loads a persistent topic, it reads the namespace policies and the topic-level policies as part of topic initialization. If a step of this initialization fails, for example because of an error reading from the metadata store, a failure loading the topic-level policies or a failure in a later initialization step, the broker logs a warning, disables the encryption requirement for that topic, and completes the topic load as if it had succeeded. The topic is then served with encryption_required not enforced, even though the namespace policy requires it. Topic-level policies that could not be loaded are also not applied.\n\nWhile the encryption requirement is not enforced, an authenticated client with permission to produce to the affected topic can publish messages that are not encrypted, and the broker accepts and stores them. This applies both to producers created after the topic was loaded and to producers that were already connected. Messages published with encryption remain encrypted; the issue does not expose the content of encrypted messages or the encryption keys.\n\nThe condition is not limited to transient failures. If the cause of the initialization failure persists, the encryption requirement is disabled again each time the topic is loaded, for example after a topic unload, a namespace bundle reassignment or a broker restart. An update to the namespace policies restores enforcement on a loaded topic, but only until the topic is loaded again. Enforcement is reliably restored only once the underlying cause of the failure has been resolved and the topic has been loaded again. The broker logs a warning when the encryption requirement is disabled, but the topic load is reported as successful and the state of the encryption requirement is not shown in the topic statistics.\n\nIn fixed versions, a failure during topic initialization causes the topic load to fail so that it can be retried, instead of loading the topic with the encryption requirement disabled.\n\nThis issue affects Apache Pulsar versions from 1.22.0-incubating before 4.0.14 and from 4.1.0 before 4.2.5.\n\n- 4.0.x version users should upgrade to at least 4.0.14.\n- 4.1.x and 4.2.x version users should upgrade to at least 4.2.5.\n\nUsers operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions.\n\nThe currently supported Apache Pulsar release lines are 4.0.x and 5.0.x. The supported versions schedule is available at https://pulsar.apache.org/contribute/release-policy/.\n\nUsers who rely on encryption_required and cannot upgrade immediately can monitor the broker logs for warnings containing \"isEncryptionRequired will be set to false\" (the exact wording of the message differs between releases), resolve the underlying cause of the failure, and then reload the affected topic and confirm that the warning does not recur.","summary":"When a Pulsar broker fails during topic initialization, it logs a warning and loads the topic with the namespace's encryption_required policy turned off. An authenticated client allowed to produce to that topic can then publish unencrypted messages, which the broker accepts and stores.","severity":"low","cvss":2.3,"epss":0.00293,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["apache-pulsar","messaging","package","self-hosted"],"not_affected_if":["encryption-required-not-used","patched-version"],"how_to_check":"- Check the Pulsar broker version with `pulsar version` and compare it to the affected ranges: 1.22.0-incubating before 4.0.14, and 4.1.0 before 4.2.5.\n- Search broker logs for the warning text \"isEncryptionRequired will be set to false\".\n- Check whether namespaces set the encryption_required policy.","fix":"- Upgrade Apache Pulsar 4.0.x to at least `4.0.14`.\n- Upgrade Apache Pulsar 4.1.x and 4.2.x to at least `4.2.5`.\n- Until upgraded, monitor broker logs for the warning, resolve the cause of the failure, then reload the affected topic and confirm the warning does not recur.","status":"open","published_at":"2026-10-21T19:16:55+00:00","first_seen_at":"2026-10-23T21:57:29+00:00","triaged_at":"2026-10-25T04:49:41+00:00","updated_at":"2026-10-25T04:49:41+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-25T04:49:41Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Apache Pulsar 4.0.x to at least `4.0.14`.\n- Upgrade Apache Pulsar 4.1.x and 4.2.x to at least `4.2.5`.\n- Until upgraded, monitor broker logs for the warning, resolve the cause of the failure, then reload the affected topic and confirm the warning does not recur.","reach":"network","title":"Apache Pulsar: failed topic load silently disables required message encryption","impact":"low","summary":"When a Pulsar broker fails during topic initialization, it logs a warning and loads the topic with the namespace's encryption_required policy turned off. An authenticated client allowed to produce to that topic can then publish unencrypted messages, which the broker accepts and stores.","category":"package","nicknames":[],"who_cares":["apache-pulsar","self-hosted","messaging"],"confidence":0.8,"needs_auth":"yes","worst_case":"unencrypted messages get stored despite encryption-required policy","analyst_note":"","how_to_check":"- Check the Pulsar broker version with `pulsar version` and compare it to the affected ranges: 1.22.0-incubating before 4.0.14, and 4.1.0 before 4.2.5.\n- Search broker logs for the warning text \"isEncryptionRequired will be set to false\".\n- Check whether namespaces set the encryption_required policy.","needs_analyst":false,"not_affected_if":["patched-version","encryption-required-not-used"],"who_is_affected":"Teams running Apache Pulsar brokers in the affected version ranges that rely on the namespace encryption_required policy to force end-to-end encryption. Exposure needs an initialization failure on topic load and a client with produce permission on the topic. Teams on patched versions or without encryption_required set can skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.000749,"input_tokens":4203,"output_tokens":658,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-105933':13A,16A '-2026':12A,15A '/contribute/release-policy/.':515C '1.22.0':443C '4.0':452C,501C '4.0.14':446C,461C '4.1':462C '4.1.0':449C '4.2':465C '4.2.5':451C,474C '5.0':504C 'accept':67B,247C 'administr':74C 'affect':235C,438C,560C 'aforement':487C 'allow':53B,72C 'alreadi':267C 'also':216C 'apach':1A,18B,70C,439C,496C 'apache-pulsar':17B 'appli':218C,252C 'authent':51B,227C 'avail':511C 'broker':28B,66B,102C,112C,168C,246C,329C,374C,529C 'bundl':325C 'cannot':523C 'caus':299C,359C,414C,552C 'client':52B,228C 'complet':180C 'condit':290C 'confirm':563C 'connect':268C 'contain':533C 'content':281C 'could':211C 'creat':256C 'current':494C 'cve':11A,14A 'differ':546C 'disabl':7A,172C,309C,383C,435C 'encrypt':10A,45B,82C,92C,109C,174C,195C,221C,243C,272C,274C,283C,287C,306C,380C,397C,433C,520C 'end':78C,80C 'end-to-end':77C 'enforc':198C,225C,338C,351C 'error':145C 'even':199C 'exact':541C 'exampl':141C,318C 'expos':279C 'fail':3A,29B,139C,419C 'failur':152C,161C,296C,303C,362C,410C,555C 'fals':539C 'fix':407C 'host':24B 'immedi':525C 'incub':444C 'initi':32B,132C,138C,165C,302C,413C 'instead':426C 'isencryptionrequir':534C 'issu':276C,437C 'key':288C 'later':164C 'least':460C,473C 'level':126C,157C,208C 'limit':293C 'line':499C 'list':481C 'load':5A,38B,113C,153C,183C,214C,261C,316C,341C,349C,371C,387C,417C,428C 'log':34B,169C,375C,530C 'messag':9A,20B,63B,81C,104C,239C,269C,284C,545C 'metadata':149C 'monitor':527C 'namespac':43B,88C,94C,120C,202C,324C,335C 'newer':491C 'oper':476C 'packag':21B 'part':129C 'patch':488C 'permiss':230C 'persist':115C,304C 'polici':47B,95C,98C,121C,127C,158C,203C,209C,336C 'prior':478C 'produc':55B,232C,255C,264C 'publish':61B,107C,238C,270C 'pulsar':2A,19B,27B,71C,440C,497C 'pulsar.apache.org':514C 'pulsar.apache.org/contribute/release-policy/.':513C 'read':118C,146C 'reassign':326C 'recur':569C 'reject':103C 'releas':498C,548C 'reli':518C 'reliabl':353C 'reload':558C 'remain':273C 'report':389C 'requir':8A,46B,76C,93C,175C,196C,204C,222C,307C,381C,398C,434C,521C 'resolv':365C,549C 'restart':330C 'restor':337C,354C 'retri':425C 'schedul':509C 'self':23B 'self-host':22B 'serv':193C 'set':90C,100C,537C 'shown':401C 'silent':6A 'state':394C 'statist':405C 'step':135C,166C 'store':69B,150C,249C 'succeed':188C 'success':391C 'support':495C,507C 'though':200C 'time':312C 'topic':4A,31B,40B,58B,85C,116C,125C,131C,156C,178C,182C,190C,207C,236C,259C,314C,321C,342C,347C,368C,386C,404C,412C,416C,430C,561C 'topic-level':124C,155C,206C 'transient':295C 'turn':48B 'under':358C,551C 'unencrypt':62B 'unload':322C 'updat':332C 'upgrad':457C,470C,484C,524C 'user':455C,468C,475C,516C 'version':408C,441C,454C,467C,477C,489C,492C,508C 'warn':36B,171C,377C,532C,566C 'without':108C 'word':542C 'x':453C,463C,466C,502C,505C","nicknames":[],"mitigations":[],"who_affected":"Teams running Apache Pulsar brokers in the affected version ranges that rely on the namespace encryption_required policy to force end-to-end encryption. Exposure needs an initialization failure on topic load and a client with produce permission on the topic. Teams on patched versions or without encryption_required set can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-21T19:16:55+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/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":"security@apache.org","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-105933","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105933","severity":null,"published_at":"2026-10-21T19:16:55+00:00","modified_at":"2026-10-22T16:56:52+00:00","first_seen_at":"2026-10-23T21:57:29+00:00","fetched_at":"2026-10-23T22:29:02+00:00","note":null},{"source":"epss","external_id":"CVE-2026-105933","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-105933","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"}