{"id":"CVE-2026-57565","title":"Readest: Cross-tenant object write via unsanitized fileName in /api/storage/upload (object-key path traversal)","summary":"Readest is a modern, feature-rich ebook reader designed for seamless cross-platform access and an intuitive reading experience. Prior to 0.11.10, the apps/readest-app/src/pages/api/storage/upload.ts route constructed an object key from t…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","cvssSource":"cna","cwe":["CWE-22"],"vendor":"readest","product":"readest","affected":["readest < 0.11.10"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:05:26.746679Z"},"exploitAvailable":true,"published":"2026-11-04","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:11:46.274Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-57565","references":[{"url":"https://github.com/readest/readest/security/advisories/GHSA-mfmj-2frf-vhgw","label":"https://github.com/readest/readest/security/advisories/GHSA-mfmj-2frf-vhgw"},{"url":"https://github.com/readest/readest/pull/4638","label":"https://github.com/readest/readest/pull/4638"},{"url":"https://github.com/readest/readest/commit/495783d04516d05b2eb10f8f8bad297d436b36de","label":"https://github.com/readest/readest/commit/495783d04516d05b2eb10f8f8bad297d436b36de"},{"url":"https://github.com/readest/readest/releases/tag/v0.11.10","label":"https://github.com/readest/readest/releases/tag/v0.11.10"}],"tags":["cve.org","exploit-available"],"epss":0.01036,"epssPercentile":0.64096,"ingestedAt":"2026-11-05T22:38:31.730Z","slug":"CVE-2026-57565","body":"## Overview\n\nReadest is a modern, feature-rich ebook reader designed for seamless cross-platform access and an intuitive reading experience. Prior to 0.11.10, the apps/readest-app/src/pages/api/storage/upload.ts route constructed an object key from the authenticated user's identifier and a client-controlled fileName without rejecting path separators or parent-directory traversal. In the R2 backend, apps/readest-app/src/utils/r2.ts placed that key into a new Request URL before signing it, and URL normalization collapsed parent-directory components so the resulting presigned PUT could escape the caller's namespace. An authenticated attacker who knew a target user identifier and book hash could overwrite or poison that user's stored book object and corrupt the associated file_key metadata; the exact cross-tenant escape was verified for the R2 backend. This issue is fixed in version 0.11.10.\n\n## Affected\n\n- `readest < 0.11.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":35.8,"likelihood":0.2,"exploitation":12,"ransomware":0},"changes":[]}