Auth bypass in Siyuan-Note Siyuan

CVE-2026-45147

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, POST /api/tag/getTag is registered with model.CheckAuth only, omitting both model.CheckAdminRole and model.CheckReadonly, despite the handler performing a configuration write that is normally guarded by both. Any authenticated user — including publish-service RoleReader accounts and RoleEditor accounts on a read-only workspace — can call this endpoint with a sort argument to mutate model.Conf.Tag.Sort and trigger model.Conf.Save(), which atomically rewrites the entire workspace conf.json. This vulnerability is fixed in 3.7.0.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (15.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-45147: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-45147?
CVE-2026-45147 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Improper Authorization. CVSS score: 4.3/10. Published 2026-05-14.
How severe is CVE-2026-45147?
Medium severity. CVSS v3 base score is 4.3 out of 10.