# CVE-2026-59815: Joplin: Pending share recipients can write items into shared folders before accepting invitations

> An authenticated user with a pending share invitation can inject content into shared folders before accepting the invitation, affecting Joplin Server users.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-qq59-gg3w-pf7v

## What is CVE-2026-59815?

CVE-2026-59815 is a medium-severity missing authorization vulnerability in laurent22 joplin, published on 21 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.7, Joplin Server's ItemModel.checkIfAllowed() authorizes writes to items with a share ID when any share_users row exists for the caller, without requiring ShareUserStatus.Accepted. A low-privileged authenticated user with a pending folder-share invitation can create an item under the share ID, and ShareModel.updateSharedItems3() propagates the injected content to the owner and accepted participants before the attacker accepts the invitation. This issue is fixed in version 3.7.7.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-59815?


## How do I fix CVE-2026-59815?

No fix has been published for CVE-2026-59815 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-59815 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59815 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59815 and fix it if it is affected.

What it is: CVE-2026-59815 is a medium-severity missing authorization vulnerability in laurent22 joplin, published on 21 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59815 exists.

Affected product: laurent22 joplin. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-59815/ (Markdown: https://insights.sbomify.com/CVE-2026-59815/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59815
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59815
- OSV: https://osv.dev/vulnerability/CVE-2026-59815

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-59815/
Summaries are generated and may contain mistakes; the official description above is the record.