{"id":"CVE-2026-107615","state":"PUBLISHED","title":"DLL search order hijacking via screenhooks libraries in TightVNC Server","description":"An uncontrolled search path element vulnerability in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to execute arbitrary code with SYSTEM privileges. DynamicLibrary::init() (and ThemeLib) load screenhooks32.dll / screenhooks64.dll with LoadLibrary() using a bare file name and no LOAD_LIBRARY_SEARCH_* flags, so the TightVNC service follows the default DLL search order and loads an attacker-planted DLL from a writable directory earlier in that order (for example, an installation directory with permissive ACLs).","publishedAt":"2026-10-08T13:39:59.358Z","updatedAt":"2026-10-08T14:00:27.042Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"securin"},"assigner":"securin","products":["GlavSoft TightVNC"],"affected":[{"vendor":"GlavSoft","product":"TightVNC","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.8.88","versionType":"custom"}],"platforms":["Windows"],"modules":["TightVNC Server (screen hooks loader)"],"programFiles":["DynamicLibrary.cpp","ThemeLib.cpp"],"programRoutines":[{"name":"DynamicLibrary::init()"}]}],"references":["https://sourceforge.net/p/vnc-tight/bugs/1666/","https://www.tightvnc.com/whatsnew.php"],"weaknesses":["CWE-427"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/107xxx/CVE-2026-107615.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-107615","state":"PUBLISHED","datePublished":"2026-10-08T13:39:59.358Z","dateUpdated":"2026-10-08T14:00:27.042Z","assignerShortName":"securin","assignerOrgId":"33c584b5-0579-4c06-b2a0-8d8329fcab9c","dateReserved":"2026-10-08T13:23:07.677Z"},"containers":{"cna":{"title":"DLL search order hijacking via screenhooks libraries in TightVNC Server","descriptions":[{"lang":"en","value":"An uncontrolled search path element vulnerability in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to execute arbitrary code with SYSTEM privileges. DynamicLibrary::init() (and ThemeLib) load screenhooks32.dll / screenhooks64.dll with LoadLibrary() using a bare file name and no LOAD_LIBRARY_SEARCH_* flags, so the TightVNC service follows the default DLL search order and loads an attacker-planted DLL from a writable directory earlier in that order (for example, an installation directory with permissive ACLs)."}],"affected":[{"vendor":"GlavSoft","product":"TightVNC","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.8.88","versionType":"custom"}],"platforms":["Windows"],"modules":["TightVNC Server (screen hooks loader)"],"programFiles":["DynamicLibrary.cpp","ThemeLib.cpp"],"programRoutines":[{"name":"DynamicLibrary::init()"}]}],"references":[{"url":"https://sourceforge.net/p/vnc-tight/bugs/1666/","name":"TightVNC bug #1666","tags":["issue-tracking"]},{"url":"https://www.tightvnc.com/whatsnew.php","name":"TightVNC release notes (2.8.88)","tags":["release-notes","patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-427","lang":"en","type":"CWE","description":"CWE-427 Uncontrolled Search Path Element"}]}],"providerMetadata":{"shortName":"securin","orgId":"33c584b5-0579-4c06-b2a0-8d8329fcab9c","dateUpdated":"2026-10-08T13:39:59.358Z"},"solutions":[{"lang":"en","value":"Upgrade TightVNC for Windows to version 2.8.88 or later."}],"credits":[{"lang":"en","type":"finder","value":"Arjun Basnet from Securin"}],"timeline":[{"time":"2026-05-30T00:00:00.000Z","lang":"en","value":"Reported to GlavSoft"},{"time":"2026-06-02T00:00:00.000Z","lang":"en","value":"Vendor acknowledged"},{"time":"2026-06-19T00:00:00.000Z","lang":"en","value":"TightVNC 2.8.88 released with fix"}],"source":{"discovery":"EXTERNAL"},"impacts":[{"capecId":"CAPEC-471","descriptions":[{"lang":"en","value":"CAPEC-471 Search Order Hijacking"}]}],"workarounds":[{"lang":"en","value":"Ensure the TightVNC installation directory and every directory on the system PATH are writable only by administrators."}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-08T14:00:03.531511Z","id":"CVE-2026-107615","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-08T14:00:27.042Z"}}]}}}