{"id":"CVE-2026-55086","state":"PUBLISHED","title":"Etherpad: Import/export use Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite","description":"Etherpad is a real-time collaborative editor. Prior to 3.1.0, src/node/handler/ImportHandler.ts and src/node/handler/ExportHandler.ts derive temporary filenames from Math.random() and place them in os.tmpdir(). On a host with a shared world-writable temporary directory, a local unprivileged attacker who predicts a filename can precreate a symbolic link to a file writable by the Etherpad process. Subsequent import or export operations can follow the link through fs.writeFile, fs.rename, or document-conversion output and overwrite the target with partially attacker-controlled content. This issue is fixed in version 3.1.0.","publishedAt":"2026-08-19T19:35:46.851Z","updatedAt":"2026-08-25T13:59:03.366Z","severity":{"score":4.2,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["ether etherpad"],"affected":[{"vendor":"ether","product":"etherpad","versions":[{"version":"< 3.1.0","status":"affected"}]}],"references":["https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h","https://github.com/ether/etherpad/pull/7784","https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996","https://github.com/ether/etherpad/releases/tag/v3.1.0"],"weaknesses":["CWE-59","CWE-377"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55086.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55086","state":"PUBLISHED","datePublished":"2026-08-19T19:35:46.851Z","dateUpdated":"2026-08-25T13:59:03.366Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T14:41:54.578Z"},"containers":{"cna":{"title":"Etherpad: Import/export use Math.random() for temp file paths; predictable paths on shared /tmp enable symlink-based file overwrite","descriptions":[{"lang":"en","value":"Etherpad is a real-time collaborative editor. Prior to 3.1.0, src/node/handler/ImportHandler.ts and src/node/handler/ExportHandler.ts derive temporary filenames from Math.random() and place them in os.tmpdir(). On a host with a shared world-writable temporary directory, a local unprivileged attacker who predicts a filename can precreate a symbolic link to a file writable by the Etherpad process. Subsequent import or export operations can follow the link through fs.writeFile, fs.rename, or document-conversion output and overwrite the target with partially attacker-controlled content. This issue is fixed in version 3.1.0."}],"affected":[{"vendor":"ether","product":"etherpad","versions":[{"version":"< 3.1.0","status":"affected"}]}],"references":[{"url":"https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h","name":"https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/ether/etherpad/pull/7784","name":"https://github.com/ether/etherpad/pull/7784","tags":["x_refsource_MISC"]},{"url":"https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996","name":"https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996","tags":["x_refsource_MISC"]},{"url":"https://github.com/ether/etherpad/releases/tag/v3.1.0","name":"https://github.com/ether/etherpad/releases/tag/v3.1.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"NONE","baseScore":4.2,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-59","lang":"en","description":"CWE-59: Improper Link Resolution Before File Access ('Link Following')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-377","lang":"en","description":"CWE-377: Insecure Temporary File","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-19T19:35:46.851Z"},"source":{"advisory":"GHSA-2jwf-f4xq-f24h","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/ether/etherpad/security/advisories/GHSA-2jwf-f4xq-f24h","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-25T13:58:06.173795Z","id":"CVE-2026-55086","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":"2026-08-25T13:59:03.366Z"}}]}}}