# CVE-2026-50553: Note Mark: Path traversal via unsanitized book/note slug in migrate export (sibling of GHSA-g49p)

> Attackers can write arbitrary files outside the export directory via unsanitized slugs, potentially gaining root privileges if the export runs as root.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 4 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** GHSA-rqrh-8wpv-x7hh, GO-2026-5949

## What is CVE-2026-50553?

CVE-2026-50553 is a high-severity path traversal vulnerability in enchant97 note-mark, published on 4 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Note Mark is an open-source note-taking application. Prior to version 0.19.5, Note Mark validates book and note slug values with the OpenAPI/huma tag pattern:"[a-z0-9-]+". huma compiles this with regexp.MustCompile(s.Pattern) and tests it with patternRe.MatchString(str), an UNANCHORED match. Because the pattern is not anchored (^...$), any string that merely CONTAINS one [a-z0-9-] substring passes validation. A slug such as ../../../../../../tmp/escape is accepted and stored verbatim. The data-export CLI commands (note-mark migrate export and note-mark migrate export-v1) join these unsanitized slugs straight into the output path with path.Join / filepath.Join, then os.MkdirAll the directory and os.Create the note file. path.Join resolves the ../ segments, so the note content file is written OUTSIDE the configured export directory. The export process commonly runs as root (default in Docker / bare-metal admin usage), so this is a root-privilege arbitrary directory create + file write. This issue has been patched in version 0.19.5.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-50553?

3 open source packages ship an affected version, including github.com/enchant97/note-mark/backend.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/enchant97/note-mark/backend` | Go | All versions | 0.0.0-20260601210719-67b7de04308a |
| `github.com/enchant97/note-mark/backend` | Go | All versions | 0.0.0-20260601210719-67b7de04308a |
| `github.com/enchant97/note-mark/backend` | Go | All versions | 0.0.0-20260601210719-67b7de04308a |

## How do I fix CVE-2026-50553?

Upgrade github.com/enchant97/note-mark/backend to 0.0.0-20260601210719-67b7de04308a or later.

## Is CVE-2026-50553 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50553 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50553 and fix it if it is affected.

What it is: CVE-2026-50553 is a high-severity path traversal vulnerability in enchant97 note-mark, published on 4 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50553 exists.

Affected packages and fixed versions:
- github.com/enchant97/note-mark/backend (Go): affected all versions; fixed in 0.0.0-20260601210719-67b7de04308a
- github.com/enchant97/note-mark/backend (Go): affected all versions; fixed in 0.0.0-20260601210719-67b7de04308a
- github.com/enchant97/note-mark/backend (Go): affected all versions; fixed in 0.0.0-20260601210719-67b7de04308a

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-2026-50553/ (Markdown: https://insights.sbomify.com/CVE-2026-50553/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50553
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50553
- OSV: https://osv.dev/vulnerability/CVE-2026-50553

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-50553/
Summaries are generated and may contain mistakes; the official description above is the record.