{"id":"CVE-2026-31893","state":"PUBLISHED","title":"Tunnelblick arbitrary file read via symlink following in tunnelblickd","description":"Tunnelblick is an open source graphic user interface for OpenVPN on macOS. In versions 3.3beta26 through 9.0beta01, any local user can read arbitrary root-owned files by exploiting a symlink following vulnerability in tunnelblick-helper, reachable through the world-accessible tunnelblickd Unix socket. The socket is configured with mode 0666, allowing any local user to connect. No authorization check is performed on the connecting client. The tunnelblick-helper process constructs a path to config.ovpn inside a user-controlled .tblk directory and reads it as root without symlink validation. An attacker can create a .tblk configuration with a symlinked config.ovpn pointing to any file and request tunnelblickd to read it. This issue has been fixed in versions 9.0beta02.","publishedAt":"2026-05-05T18:55:41.737Z","updatedAt":"2026-05-05T19:37:47.926Z","severity":{"score":6.8,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["Tunnelblick Tunnelblick"],"affected":[{"vendor":"Tunnelblick","product":"Tunnelblick","versions":[{"version":">= 3.3beta26, < 9.0beta02","status":"affected"}]}],"references":["https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq69","https://github.com/Tunnelblick/Tunnelblick/releases/tag/v9.0beta02"],"weaknesses":["CWE-61"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31893.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31893","state":"PUBLISHED","datePublished":"2026-05-05T18:55:41.737Z","dateUpdated":"2026-05-05T19:37:47.926Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-09T21:59:02.687Z"},"containers":{"cna":{"title":"Tunnelblick arbitrary file read via symlink following in tunnelblickd","descriptions":[{"lang":"en","value":"Tunnelblick is an open source graphic user interface for OpenVPN on macOS. In versions 3.3beta26 through 9.0beta01, any local user can read arbitrary root-owned files by exploiting a symlink following vulnerability in tunnelblick-helper, reachable through the world-accessible tunnelblickd Unix socket. The socket is configured with mode 0666, allowing any local user to connect. No authorization check is performed on the connecting client. The tunnelblick-helper process constructs a path to config.ovpn inside a user-controlled .tblk directory and reads it as root without symlink validation. An attacker can create a .tblk configuration with a symlinked config.ovpn pointing to any file and request tunnelblickd to read it. This issue has been fixed in versions 9.0beta02."}],"affected":[{"vendor":"Tunnelblick","product":"Tunnelblick","versions":[{"version":">= 3.3beta26, < 9.0beta02","status":"affected"}]}],"references":[{"url":"https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq69","name":"https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq69","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Tunnelblick/Tunnelblick/releases/tag/v9.0beta02","name":"https://github.com/Tunnelblick/Tunnelblick/releases/tag/v9.0beta02","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.8,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-61","lang":"en","description":"CWE-61: UNIX Symbolic Link (Symlink) Following","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-05T18:55:41.737Z"},"source":{"advisory":"GHSA-927j-vcjf-hq69","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/Tunnelblick/Tunnelblick/security/advisories/GHSA-927j-vcjf-hq69","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-05T19:37:28.228929Z","id":"CVE-2026-31893","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-05T19:37:47.926Z"}}]}}}