# CVE-2026-72789: SiYuan before v3.7.4 Authentication Bypass via Encrypted Notebooks

> Attackers can access decrypted content from encrypted notebooks via the publish API without authentication, exposing sensitive data.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-v684-q882-jgmq, GO-2026-6434

## What is CVE-2026-72789?

CVE-2026-72789 is a critical authentication bypass vulnerability in siyuan-note siyuan, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SiYuan before v3.7.4 fails to properly validate publish access for encrypted notebooks, treating them as publicly accessible by default. Anonymous readers can enumerate and retrieve fully decrypted document content from unlocked encrypted notebooks through the publish API without authentication or key material.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-72789?

3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260726020813-a25c2dd06aae |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260726020813-a25c2dd06aae |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260726020813-a25c2dd06aae |

## How do I fix CVE-2026-72789?

Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260726020813-a25c2dd06aae or later.

## Is CVE-2026-72789 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-72789 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72789 and fix it if it is affected.

What it is: CVE-2026-72789 is a critical authentication bypass vulnerability in siyuan-note siyuan, published on 12 Aug 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-2026-72789 exists.

Affected packages and fixed versions:
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260726020813-a25c2dd06aae
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260726020813-a25c2dd06aae
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260726020813-a25c2dd06aae

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-2026-72789/ (Markdown: https://insights.sbomify.com/CVE-2026-72789/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72789
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72789
- OSV: https://osv.dev/vulnerability/CVE-2026-72789

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72789/
Summaries are generated and may contain mistakes; the official description above is the record.