CVE-2026-44522 — backend
CVE-2026-44522 is a Improper Input Validation vulnerability in github.com/enchant97/note-mark/backend. A fix is available for github.com/enchant97/note-mark/backend — see the affected versions and patch details below.
Note Mark: Arbitrary File Write via Path Traversal in Asset Names Leading to Remote Code Execution
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-2026-44522.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/enchant97/note-mark/backendReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Note Mark is an open-source note-taking application. From 0.13.0 to before 0.19.4, the Note Mark application allows authenticated users to upload assets to notes via POST /api/notes/{noteID}/assets, where the asset filename is provided through the X-Name HTTP request header. This value is stored directly in the database without any sanitization or validation - no path separator filtering, no directory traversal sequence rejection, and no use of filepath.Base() to strip directory components. The unsanitized name is persisted as-is in the note_assets table (Name column, varchar(80)). When an administrator subsequently runs the data export CLI commands (note-mark migrate export-v1 or note-mark migrate export), the stored asset name is passed directly into filepath.Join() and path.Join() calls as part of the output file path argument to os.Create(). Since Go's filepath.Join() resolves ../ sequences during path normalization, an attacker-controlled asset name containing directory traversal sequences causes the export process to write files to arbitrary locations on the filesystem, completely outside the intended export directory. This vulnerability is fixed in 0.19.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/enchant97/note-mark/backend | all versions | 0.0.0-20260501152243-db3f72bff780go get github.com/enchant97/note-mark/backend@v0.0.0-20260501152243-db3f72bff780 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/enchant97/note-mark/backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/enchant97/note-mark/backend to 0.0.0-20260501152243-db3f72bff780 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44522 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-44522 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44522. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44522 in your dependencies?
O3 Security finds CVE-2026-44522 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.