CVE-2026-93921: Auth Bypass (CVSS 4.3)

Description

SiYuan versions through 3.8.4 fail to enforce publish access control in the getDynamicIcon endpoint, allowing read-only token holders to access document metadata. Attackers can call the endpoint with type=8 and crafted content to read block titles, names, aliases, and hierarchical paths of restricted documents via template injection.

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CVSS v3.1 Score

4.3

MEDIUM

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

EPSS — Exploit Prediction

0.0038

Probability of exploitation

0.30%

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-862 Missing Authorization

References

Other References

https://github.com/siyuan-note/siyuan https://github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/api/icon.go#L546-L549 https://github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/api/router.go#L51 https://github.com/siyuan-note/siyuan/blob/v3.8.4/kernel/model/template.go#L485-L526 https://github.com/siyuan-note/siyuan/security/advisories/GHSA-whcx-xxqh-c838 https://www.vulncheck.com/advisories/siyuan-through-3.8.4-access-control-bypass-via-dynamic-icon-endpoint https://github.com/siyuan-note/siyuan/security/advisories/GHSA-whcx-xxqh-c838

Frequently Asked Questions

What is CVE-2026-93921? +

SiYuan versions through 3.8.4 fail to enforce publish access control in the getDynamicIcon endpoint, allowing read-only token holders to access document metadata. Attackers can call the endpoint with type=8 and crafted content to read block titles, names, aliases, and hierarchical paths of restricted documents via template injection. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2026-93921? +

CVE-2026-93921 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0038, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-93921? +

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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