{"id":"CVE-2026-98439","kind":"vulnerability","aliases":["CVE-2026-98439"],"related":[],"title":"Linux kernel SMB server: pending async requests can block connection close","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/server: cancel async requests when closing connection\n\nAn async request may still be waiting when a connection is closed.\nThis can stop the connection from closing.\n\nCancel active async requests before waiting for them to finish.","summary":"When a client connection to the Linux kernel's SMB server (ksmbd) closes while an asynchronous request is still waiting, the connection can fail to shut down. The fix cancels pending async requests before waiting for them to finish.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["file-server","infrastructure","kernel","ksmbd","linux","self-hosted"],"not_affected_if":["ksmbd-not-loaded"],"how_to_check":"- Run `uname -r` and compare against the fixed kernel version listed in the NVD entry (unknown in sources)\n- Check whether the SMB server is loaded with `lsmod | grep ksmbd`\n- Check whether the server is enabled with `systemctl status ksmbd` (unknown if sources do not say otherwise)","fix":"- Update the Linux kernel to a release that includes the upstream commit cancelling async requests on connection close (version unknown in sources)\n- Until patched, disable the SMB server if it is not needed (unknown in sources)","status":"open","published_at":"2026-10-18T15:16:53+00:00","first_seen_at":"2026-10-23T21:57:15+00:00","triaged_at":"2026-10-25T05:27:34+00:00","updated_at":"2026-10-25T05:27:34+00:00","category":"infrastructure","confidence":0.3,"triage":{"at":"2026-10-25T05:27:34Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Linux kernel to a release that includes the upstream commit cancelling async requests on connection close (version unknown in sources)\n- Until patched, disable the SMB server if it is not needed (unknown in sources)","reach":"network","title":"Linux kernel SMB server: pending async requests can block connection close","impact":"low","summary":"When a client connection to the Linux kernel's SMB server (ksmbd) closes while an asynchronous request is still waiting, the connection can fail to shut down. The fix cancels pending async requests before waiting for them to finish.","category":"infrastructure","nicknames":[],"who_cares":["linux","kernel","ksmbd","self-hosted","file-server"],"confidence":0.3,"needs_auth":"unknown","worst_case":"unknown; connection teardown may hang, impact beyond that not stated","analyst_note":"Sources give only the kernel commit message; check the NVD entry and the kernel stable commit for affected and fixed versions, severity, and whether this is a denial of service.","how_to_check":"- Run `uname -r` and compare against the fixed kernel version listed in the NVD entry (unknown in sources)\n- Check whether the SMB server is loaded with `lsmod | grep ksmbd`\n- Check whether the server is enabled with `systemctl status ksmbd` (unknown if sources do not say otherwise)","needs_analyst":true,"not_affected_if":["ksmbd-not-loaded"],"who_is_affected":"Systems running the Linux kernel SMB server (ksmbd) with it enabled are the ones to check. The sources do not describe a specific configuration or role beyond that, so systems that do not run ksmbd are likely unaffected.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000641,"input_tokens":3297,"output_tokens":622,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-98439':14A,17A 'activ':104C 'async':6A,59B,79C,85C,105C 'asynchron':43B 'block':9A 'cancel':57B,78C,103C 'client':30B 'close':11A,40B,82C,95C,102C 'connect':10A,31B,49B,83C,93C,100C 'cve':12A,15A 'fail':51B 'file':19B 'file-serv':18B 'finish':66B,112C 'fix':56B 'follow':72C 'host':27B 'infrastructur':21B 'kernel':2A,22B,35B,70C 'ksmbd':23B,39B 'linux':1A,24B,34B,69C 'may':87C 'pend':5A,58B 'request':7A,44B,60B,80C,86C,106C 'resolv':76C 'self':26B 'self-host':25B 'server':4A,20B,38B 'shut':53B 'smb':3A,37B 'smb/server':77C 'still':46B,88C 'stop':98C 'vulner':73C 'wait':47B,62B,90C,108C","nicknames":[],"mitigations":[],"who_affected":"Systems running the Linux kernel SMB server (ksmbd) with it enabled are the ones to check. The sources do not describe a specific configuration or role beyond that, so systems that do not run ksmbd are likely unaffected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T15:16:53+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98439","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98439","severity":null,"published_at":"2026-10-18T15:16:53+00:00","modified_at":"2026-10-19T10:18:52+00:00","first_seen_at":"2026-10-23T21:57:15+00:00","fetched_at":"2026-10-23T22:28:56+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"}