CVE-2026-22810 is a high-severity (CVSS 8.2) CWE-24 vulnerability in @joplin/onenote-converter. A fix is available for @joplin/onenote-converter — see the affected versions and patch details below.
Joplin: Path traversal in OneNote importer allows overwriting arbitrary files
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-22810.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@joplin/onenote-converternpmDescription
Summary
A path traversal vulnerability in the OneNote importer allows overwriting arbitrary files on disk.
Details
The OneNote converter does not sanitize the names of embedded files before writing them to disk. As a result, it's possible for an attacker to create a malicious .one file that includes file names containing ../../, that are then interpreted as part of the target path when extracting attachments from the .one file.
One affected location is embedded_file.rs, which generates a file name from a string previously parsed from the .one file,
https://github.com/laurent22/joplin/blob/af5108d70233b1db9410346958c1587cf7c1b16d/packages/onenote-converter/renderer/src/page/embedded_file.rs#L13-L16
Above, determine_filename passes through the provided file name.
Similar logic has been present since 4d7fa5972fe2986eae14cbf3a2801835cbe1384e (Joplin 3.2.2), when the OneNote importer was first introduced.
PoC
Screencast from 2025-11-20 13-50-21.webm
- Import poc_v2.zip.
- Open the application's profile directory, then open
log.txt. - Observe that
log.txthas been overwritten non-log-file content (a WAV file).
Tested on Fedora Linux 43 with Joplin 3.4.12 (prod, linux) and Joplin 3.5.6 (dev, linux).
Note: The PoC ZIP file overwrites Joplin's log.txt. It is also possible to craft a file that overwrites more sensitive system files (e.g. .bashrc on Linux).
Impact
This is a path traversal vulnerability that impacts all versions of Joplin (<= v3.5.6) that include a OneNote importer. Importing a crafted OneNote export file allows an attacker to overwrite arbitrary files, potentially leading to remote code execution.
Patched in
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @joplin/onenote-converter | all versions | 3.5.7npm install @joplin/onenote-converter@3.5.7 |
Affected Products
joplinjoplinappone2htmlmsiemensDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @joplin/onenote-converter, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @joplin/onenote-converter to 3.5.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-22810 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2026-22810 in your dependencies?
Find it across npm, including transitive dependencies.