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.
- 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
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.
Which versions are affected by CVE-2026-50553?
3 open source packages ship an affected version, including github.com/enchant97/note-mark/backend.
| Package | 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.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-50553 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50553 exists.
Sources
Also known as GHSA-rqrh-8wpv-x7hh, GO-2026-5949.