# CVE-2026-44588: SiYuan: URL-encoded title bypasses `escapeAriaLabel`, decoded by `decodeURIComponent` into a tooltip-XSS

> An XSS vulnerability in SiYuan allows attackers to execute arbitrary code via crafted document titles due to improper decoding in tooltip rendering.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 May 2026
- **Updated:** 15 May 2026
- **Also known as:** GHSA-25rp-h46x-2hjm, GO-2026-4993

## What is CVE-2026-44588?

CVE-2026-44588 is a critical cross-site scripting vulnerability in siyuan-note siyuan, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0,  he tooltip mouseover handler in app/src/block/popover.ts reads aria-label via getAttribute and passes it through decodeURIComponent before assigning to messageElement.innerHTML in app/src/dialog/tooltip.ts:41. The encoder used at the producer side, escapeAriaLabel in app/src/util/escape.ts:19-25, only handles HTML special characters (", ', <, literal &lt;) — it leaves %XX URL-escapes untouched. So a doc title containing %3Cimg src=x onerror=...%3E round-trips through escapeAriaLabel and the HTML attribute layer unmodified. Then decodeURIComponent on the consumer side converts %3C to a literal < character (a real <, NOT a character reference). When that string is assigned to innerHTML, the HTML5 tokenizer enters TagOpenState on the literal <, parses the <img> element, and the onerror handler fires. Because the renderer runs with nodeIntegration: true, contextIsolation: false, webSecurity: false (app/electron/main.js:407-411), require('child_process') is reachable from the injected handler, escalating to arbitrary code execution.This vulnerability is fixed in 3.7.0.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-1188 (Initialization of a Resource with an Insecure Default), CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2026-44588?

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 | None |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions to 0.0.0-20260421031503-96dfe0bea474 | None |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions to 0.0.0-20260421031503-96dfe0bea474 | None |

## How do I fix CVE-2026-44588?

Upgrade to a fixed version.

## Is CVE-2026-44588 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44588 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44588 and fix it if it is affected.

What it is: CVE-2026-44588 is a critical cross-site scripting vulnerability in siyuan-note siyuan, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44588 exists.

Affected packages and fixed versions:
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; no fix listed
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions up to 0.0.0-20260421031503-96dfe0bea474; no fix listed
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions up to 0.0.0-20260421031503-96dfe0bea474; no fix listed

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-2026-44588/ (Markdown: https://insights.sbomify.com/CVE-2026-44588/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44588
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44588
- OSV: https://osv.dev/vulnerability/CVE-2026-44588

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-44588/
Summaries are generated and may contain mistakes; the official description above is the record.