Vulnerability record · CVE-2026-49453 · published 21 September 2026
CVE-2026-49453: Improper input validation vulnerability
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, Joplin accepts synchronized resource metadata whose id or file_extension contains parent-directory or path-separator characters. BaseItem.unserialize() stores the unvalidated fields, resourceFilename() concatenates them into a destination path, and ResourceFetcher writes the attacker-controlled resource blob outside the resource directory during background synchronization. An attacker with write access to a configured sync target or shared notebook can create or overwrite files at an attacker-chosen existing path without user interaction. This issue is fixed in versions 3.6.15 and 3.7.2.
Description
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, Joplin accepts synchronized resource metadata whose id or file_extension contains parent-directory or path-separator characters. BaseItem.unserialize() stores the unvalidated fields, resourceFilename() concatenates them into a destination path, and ResourceFetcher writes the attacker-controlled resource blob outside the resource directory during background synchronization. An attacker with write access to a configured sync target or shared notebook can create or overwrite files at an attacker-chosen existing path without user interaction. This issue is fixed in versions 3.6.15 and 3.7.2.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L
References
Track CVE-2026-49453 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-49453), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
