Note Mark has a JWT Secret Weakness that allows Full Account Takeover via Token Forgery

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

10.0 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

EPSS

• CVE-2026-44523: 0.15% estimated exploitation activity in the next 30 days; percentile 4.01 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary No minimum length or entropy is enforced on the JWTSECRET configuration value. The application accepts any base64-decodable secret regardless of size, including secrets as short as 1 byte. HS256 secrets below 32 bytes are brute-forceable offline, allowing attackers to recover the signing key and forge valid JWTs for arbitrary users. --- Impact An attacker who captures a single valid JWT (e.g, from cookies, logs, or network traffic) can: \ Crack the signing secret offline using brute-force or wordlist attacks \ Forge valid JWTs for any user ID (including administrators) \ Authenticate without knowing any credentials This results in full account takeover across the entire application with no server-side detection or rate limiting possible. --- Details In backend/config/utils.go, the Base64Decoded.UnmarshalText function decodes the JWT secret but does not validate its length or entropy. In backend/core/auth.go, JWT tokens are signed using HS256 without enforcing minimum key size…

Published by the source

7 May 2026, 21:08 UTC

Last modified by the source

15 May 2026, 23:45 UTC

Source last checked

26 Oct 2026, 15:22 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-q6mh-rqwh-g786

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# Patch Next advisory brief: CVE-2026-44523

Advisory: Note Mark has a JWT Secret Weakness that allows Full Account Takeover via Token Forgery
IDs: CVE-2026-44523, GHSA-q6mh-rqwh-g786
Record: https://patchnext.com/advisories/cve-2026-44523 (revision 1, source checked 26 Oct 2026, 15:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 10.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/enchant97/note-mark/backend 0.0.0-20260501152247-18b587758667. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/enchant97/note-mark/backend: affected < 0.0.0-20260501152247-18b587758667; fixed in 0.0.0-20260501152247-18b587758667

## Suggested inspection (read-only)
- Go github.com/enchant97/note-mark/backend: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/enchant97/note-mark/backend.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-q6mh-rqwh-g786 (GitHub-reviewed advisory GHSA-q6mh-rqwh-g786 lists affected ranges: Go github.com/enchant97/note-mark/backend >=0 <0.0.0-20260501152247-18b587758667)

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