CVE-2026-44588: SiYuan: Electron Renderer RCE via decodeURIComponent-driven tooltip XSS in aria-label sink (incomplete fix for CVE-2026-34585)

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.6%, percentile 45: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 45% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Only applies if your dependency tree includes github.com/siyuan-note/siyuan/kernel (Go) <= 0.0.0-20260421031503-96dfe0bea474, no fixed version listed. Check your lockfile, including transitive dependencies.

What it is

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 (", ', element, and the onerror handler fires. Because the renderer runs with nodeIntegration: true, contextIsolation: false, webSecurity: false (app/electron/main.js:407-411), require('childprocess') is reachable from the injected handler, escalating to arbitrary code execution.This vulnerability is fixed in 3.7.0.

From the GitHub advisory

Summary

The 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 (", ', element, and the onerror handler fires.

Because the renderer runs with nodeIntegration: true, contextIsolation: false, webSecurity: false (app/electron/main.js:407-411), require('childprocess') is reachable from the injected handler, escalating to arbitrary code execution.

Doc titles, AV column names + descriptions, AV select options, file-tree tooltips all reach this sink because they're rendered into class="ariaLabel" elements with aria-label="${escapeAriaLabel(...)}". Doc title is the easiest plant — any user with create/rename access lands the payload, and the file survives .sy.zip round-trip without modification.

Why a "double HTML-decode" framing is wrong

Weakness type: CWE-79, CWE-116, CWE-1188.

Product: github.com/siyuan-note/siyuan/kernel (Go) · Assigned by: GitHub_M · Published: 2026-05-14

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: active

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.55% probability of exploitation activity in the next 30 days; percentile 45.

Timeline

• 2026-05-08 — GitHub-reviewed advisory GHSA-25rp-h46x-2hjm published (critical)
• 2026-05-14 — CVE record published by GitHub_M
• 2026-05-15 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-25rp-h46x-2hjm github.com
2. CVE.org record CVE-2026-44588 cve.org
3. NVD entry CVE-2026-44588 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com

Critical Go advisories · Today’s Security Digest