{"affected":[{"product":"readest","source":"CNA: GitHub_M","vendor":"readest","versions":[{"status":"affected","version":"< 0.11.10"}]}],"cveId":"CVE-2026-57565","cwes":["CWE-22"],"description":"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 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.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":6.5,"severity":"medium","source":"CNA: GitHub_M","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}],"modifiedAt":1793828721130,"publishedAt":1793828721130,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/readest/readest/security/advisories/GHSA-mfmj-2frf-vhgw"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/readest/readest/pull/4638"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/readest/readest/commit/495783d04516d05b2eb10f8f8bad297d436b36de"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/readest/readest/releases/tag/v0.11.10"}],"remediation":[],"revision":"c00d23c4d868e4d2b564dd928c0d5c772e304fd290e6e5b8ae03bc76327fb85a","sources":[{"modifiedAt":1793828721130,"name":"CNA: GitHub_M","retrievedAt":1793830387082,"url":"https://www.cve.org/CVERecord?id=CVE-2026-57565"}],"ssvc":null,"status":"published","title":"Readest: Cross-tenant object write via unsanitized fileName in /api/storage/upload (object-key path traversal)","updatedAt":1793830387082}