CVE-2026-87814: XSS (CVSS 7.3)

Description

SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in the search asset preview feature that fails to escape indexed asset content before inserting it into the DOM using innerHTML. Attackers who can place crafted text assets in a workspace can execute JavaScript in the SiYuan origin when victims preview the assets, enabling authenticated API requests and workspace manipulation.

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CVSS v3.1 Score

7.3

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-64gp-333q-mq6j https://www.vulncheck.com/advisories/siyuan-before-3.8.2-stored-xss-via-asset-preview

Frequently Asked Questions

What is CVE-2026-87814? +

SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in the search asset preview feature that fails to escape indexed asset content before inserting it into the DOM using innerHTML. Attackers who can place crafted text assets in a workspace can execute JavaScript in the SiYuan origin when victims preview the assets, enabling authenticated API requests and workspace manipulation. It has a CVSS v3.1 base score of 7.3 (HIGH).

How severe is CVE-2026-87814? +

CVE-2026-87814 has a CVSS v3.1 score of 7.3 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0021, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-87814? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-87814