{"id":"CVE-2026-105520","kind":"vulnerability","aliases":["CVE-2026-105520"],"related":[],"title":"Windows DNS: link following lets an authorized user gain privileges","description":"Improper link resolution before file access ('link following') in Windows DNS allows an authorized attacker to elevate privileges over a network.","summary":"Windows DNS resolves a symbolic or hard link before accessing a file, so a user with some access can be tricked into reading or writing a file they should not reach. An attacker with valid credentials on the network can elevate their privileges.","severity":"high","cvss":7.2,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Windows DNS","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["infrastructure","self-hosted","windows","windows-dns"],"not_affected_if":["no-dns-server-role"],"how_to_check":"- Confirm the Windows DNS Server role is installed on the host (`Get-WindowsFeature DNS` in PowerShell).\n- Check the build with `winver` and compare it with the fixed build in Microsoft's advisory for CVE-2026-105520.","fix":null,"status":"open","published_at":"2026-11-10T19:17:51+00:00","first_seen_at":"2026-11-10T19:24:17+00:00","triaged_at":"2026-11-10T19:47:57+00:00","updated_at":"2026-11-10T19:47:57+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-10T19:47:57Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Windows DNS: link following lets an authorized user gain privileges","impact":"high","summary":"Windows DNS resolves a symbolic or hard link before accessing a file, so a user with some access can be tricked into reading or writing a file they should not reach. An attacker with valid credentials on the network can elevate their privileges.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","windows-dns","self-hosted"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"authorized attacker elevates privileges on the DNS server","analyst_note":"Find the Microsoft advisory for CVE-2026-105520 to confirm affected builds, the fixed update and any workaround.","how_to_check":"- Confirm the Windows DNS Server role is installed on the host (`Get-WindowsFeature DNS` in PowerShell).\n- Check the build with `winver` and compare it with the fixed build in Microsoft's advisory for CVE-2026-105520.","plain_action":"","product_name":"Windows DNS","needs_analyst":true,"not_affected_if":["no-dns-server-role"],"who_is_affected":"Organisations running Windows Server as a DNS server. The sources do not say which Windows builds are affected, and they do not give a fixed version. Hosts that do not run the DNS Server role are not exposed through this flaw.","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000723,"input_tokens":4490,"output_tokens":549,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find the Microsoft advisory for CVE-2026-105520 to confirm affected builds, the fixed update and any workaround.","search":"'-105520':13A,16A '-2026':12A,15A 'access':36B,44B,75C 'allow':81C 'attack':59B,84C 'author':7A,83C 'credenti':62B 'cve':11A,14A 'dns':2A,18A,26B,28B,80C 'elev':67B,86C 'file':38B,53B,74C 'follow':4A,77C 'gain':9A 'hard':33B 'host':22B 'improp':70C 'infrastructur':19B 'let':5A 'link':3A,34B,71C,76C 'network':65B,90C 'privileg':10A,69B,87C 'reach':57B 'read':49B 'resolut':72C 'resolv':29B 'self':21B 'self-host':20B 'symbol':31B 'trick':47B 'user':8A,41B 'valid':61B 'window':1A,23B,25B,27B,79C 'windows':17A 'windows-dn':24B 'write':51B","nicknames":[],"mitigations":[],"who_affected":"Organisations running Windows Server as a DNS server. The sources do not say which Windows builds are affected, and they do not give a fixed version. Hosts that do not run the DNS Server role are not exposed through this flaw.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":["dns","windowsdns"],"ptokens":["dns","windows"],"labels":["high","infrastructure","selfhosted","vendor","windows","windowsdns"],"campaign_type":null,"search_a":"'-105520':13A,16A '-2026':12A,15A 'author':7A 'cve':11A,14A 'dns':2A,18A 'follow':4A 'gain':9A 'let':5A 'link':3A 'privileg':10A 'user':8A 'window':1A 'windows':17A","search_b":"'access':36B,44B 'attack':59B 'credenti':62B 'dns':26B,28B 'elev':67B 'file':38B,53B 'hard':33B 'host':22B 'infrastructur':19B 'link':34B 'network':65B 'privileg':69B 'reach':57B 'read':49B 'resolv':29B 'self':21B 'self-host':20B 'symbol':31B 'trick':47B 'user':41B 'valid':61B 'window':23B,25B,27B 'windows-dn':24B 'write':51B","search_c":"'access':75C 'allow':81C 'attack':84C 'author':83C 'dns':80C 'elev':86C 'file':74C 'follow':77C 'improp':70C 'link':71C,76C 'network':90C 'privileg':87C 'resolut':72C 'window':79C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:17:51+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-105520","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105520","severity":null,"published_at":"2026-11-10T19:17:51+00:00","modified_at":"2026-11-10T19:17:51+00:00","first_seen_at":"2026-11-10T19:24:17+00:00","fetched_at":"2026-11-10T19:24:17+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"}