# CVE-2026-41571: Note Mark: OIDC-registered users authenticated by submitting password "null"

> Attackers can authenticate as OIDC users by submitting the password 'null', gaining unauthorized access to their accounts.

- **Severity:** Critical 9.4 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 May 2026
- **Updated:** 4 May 2026
- **Also known as:** GHSA-pxf8-6wqm-r6hh, GO-2026-5557

## What is CVE-2026-41571?

CVE-2026-41571 is a critical authentication bypass vulnerability in enchant97 note-mark, published on 4 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Note Mark is an open-source note-taking application. In version 0.19.2, IsPasswordMatch in backend/db/models.go falls back to a hard-coded bcrypt("null") placeholder whenever a user has no stored password. OIDC-registered users are created with an empty password, so anyone who submits password: "null" to the internal login endpoint receives a valid session for that user. The bypass is unauthenticated and requires no user interaction. This issue has been patched in version 0.19.3.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-41571?

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 | 0.0.0-20260417132909-dea5530cc989 |
| `github.com/enchant97/note-mark/backend` | Go | All versions | 0.0.0-20260417132909-dea5530cc989 |
| `github.com/enchant97/note-mark/backend` | Go | All versions | 0.0.0-20260417132909-dea5530cc989 |

## How do I fix CVE-2026-41571?

Upgrade github.com/enchant97/note-mark/backend to 0.0.0-20260417132909-dea5530cc989 or later.

## Is CVE-2026-41571 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41571 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41571 and fix it if it is affected.

What it is: CVE-2026-41571 is a critical authentication bypass vulnerability in enchant97 note-mark, published on 4 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41571 exists.

Affected packages and fixed versions:
- github.com/enchant97/note-mark/backend (Go): affected all versions; fixed in 0.0.0-20260417132909-dea5530cc989
- github.com/enchant97/note-mark/backend (Go): affected all versions; fixed in 0.0.0-20260417132909-dea5530cc989
- github.com/enchant97/note-mark/backend (Go): affected all versions; fixed in 0.0.0-20260417132909-dea5530cc989

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-2026-41571/ (Markdown: https://insights.sbomify.com/CVE-2026-41571/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41571
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41571
- OSV: https://osv.dev/vulnerability/CVE-2026-41571

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41571/
Summaries are generated and may contain mistakes; the official description above is the record.