{"id":"CVE-2026-18792","kind":"vulnerability","aliases":["CVE-2026-18792"],"related":[],"title":"Synology DSM: Sharing API path flaw lets logged-in users read or write files","description":"An improper limitation of a pathname to a restricted directory vulnerability in the Sharing API in Synology DiskStation Manager (DSM) before 7.3.2-86009-5 and 7.4.1-90080-1 allows remote authenticated users to read or write arbitrary files and conduct denial-of-service attacks.","summary":"Synology DiskStation Manager has a path-traversal flaw in its Sharing API that lets a remote, logged-in user read or write arbitrary files on the NAS. It can also be used to cause a denial of service.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["dsm","infrastructure","nas","self-hosted","synology"],"not_affected_if":["no-untrusted-accounts","patched-dsm"],"how_to_check":"- Check the DSM version under Control Panel > Info Center, or run `cat /etc/VERSION` over SSH if enabled\n- Compare the result against the fixed versions listed below","fix":"- DSM `7.3.2-86009-5` or later on the 7.3 branch\n- DSM `7.4.1-90080-1` or later on the 7.4 branch","status":"open","published_at":"2026-11-12T04:17:19+00:00","first_seen_at":"2026-11-12T04:47:09+00:00","triaged_at":"2026-11-12T04:47:35+00:00","updated_at":"2026-11-12T04:47:35+00:00","category":"infrastructure","confidence":0.7,"triage":{"at":"2026-11-12T04:47:35Z","model":"claude-haiku-5-5","output":{"fix":"- DSM `7.3.2-86009-5` or later on the 7.3 branch\n- DSM `7.4.1-90080-1` or later on the 7.4 branch","reach":"network","title":"Synology DSM: Sharing API path flaw lets logged-in users read or write files","impact":"high","summary":"Synology DiskStation Manager has a path-traversal flaw in its Sharing API that lets a remote, logged-in user read or write arbitrary files on the NAS. It can also be used to cause a denial of service.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["synology","dsm","nas","self-hosted"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"attacker reads or writes arbitrary files and disrupts service","analyst_note":"Sources do not state whether a non-default configuration is required.","how_to_check":"- Check the DSM version under Control Panel > Info Center, or run `cat /etc/VERSION` over SSH if enabled\n- Compare the result against the fixed versions listed below","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["patched-dsm","no-untrusted-accounts"],"who_is_affected":"Any Synology NAS running DSM before the fixed versions, reachable by a remote user who holds a valid DSM account. Systems where DSM is not exposed to untrusted accounts are at lower risk. unknown whether the flaw depends on a non-default Sharing feature.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000734,"input_tokens":4556,"output_tokens":556,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-1':96C '-18792':18A,21A '-2026':17A,20A '-5':92C '-86009':91C '-90080':95C '7.3.2':90C '7.4.1':94C 'allow':97C 'also':60B 'api':4A,41B,83C 'arbitrari':53B,105C 'attack':113C 'authent':99C 'caus':64B 'conduct':108C 'cve':16A,19A 'denial':66B,110C 'denial-of-servic':109C 'directori':78C 'diskstat':30B,86C 'dsm':2A,22B,88C 'file':15A,54B,106C 'flaw':6A,37B 'host':27B 'improp':70C 'infrastructur':23B 'let':7A,43B 'limit':71C 'log':9A,47B 'logged-in':8A,46B 'manag':31B,87C 'nas':24B,57B 'path':5A,35B 'path-travers':34B 'pathnam':74C 'read':12A,50B,102C 'remot':45B,98C 'restrict':77C 'self':26B 'self-host':25B 'servic':68B,112C 'share':3A,40B,82C 'synolog':1A,28B,29B,85C 'travers':36B 'use':62B 'user':11A,49B,100C 'vulner':79C 'write':14A,52B,104C","nicknames":[],"mitigations":[],"who_affected":"Any Synology NAS running DSM before the fixed versions, reachable by a remote user who holds a valid DSM account. Systems where DSM is not exposed to untrusted accounts are at lower risk. unknown whether the flaw depends on a non-default Sharing feature.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["dsm","high","infrastructure","nas","selfhosted","synology"],"campaign_type":null,"search_a":"'-18792':18A,21A '-2026':17A,20A 'api':4A 'cve':16A,19A 'dsm':2A 'file':15A 'flaw':6A 'let':7A 'log':9A 'logged-in':8A 'path':5A 'read':12A 'share':3A 'synolog':1A 'user':11A 'write':14A","search_b":"'also':60B 'api':41B 'arbitrari':53B 'caus':64B 'denial':66B 'diskstat':30B 'dsm':22B 'file':54B 'flaw':37B 'host':27B 'infrastructur':23B 'let':43B 'log':47B 'logged-in':46B 'manag':31B 'nas':24B,57B 'path':35B 'path-travers':34B 'read':50B 'remot':45B 'self':26B 'self-host':25B 'servic':68B 'share':40B 'synolog':28B,29B 'travers':36B 'use':62B 'user':49B 'write':52B","search_c":"'-1':96C '-5':92C '-86009':91C '-90080':95C '7.3.2':90C '7.4.1':94C 'allow':97C 'api':83C 'arbitrari':105C 'attack':113C 'authent':99C 'conduct':108C 'denial':110C 'denial-of-servic':109C 'directori':78C 'diskstat':86C 'dsm':88C 'file':106C 'improp':70C 'limit':71C 'manag':87C 'pathnam':74C 'read':102C 'remot':98C 'restrict':77C 'servic':112C 'share':82C 'synolog':85C 'user':100C 'vulner':79C 'write':104C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-12T04:17:19+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"security@synology.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-18792","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18792","severity":null,"published_at":"2026-11-12T04:17:19+00:00","modified_at":"2026-11-12T04:17:19+00:00","first_seen_at":"2026-11-12T04:47:09+00:00","fetched_at":"2026-11-12T04:47:09+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"}