CVE-2026-50553

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-04 20:37 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-09-04 18:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-09-09 21:09 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-09-04 18:17 UTC

Last modified

2026-09-09 21:09 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Deferred

Attack profile CVSS 4.0 · 8.6

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

Passive

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-50553.md and follow it. Check whether this project is affected by CVE-2026-50553. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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