What is CVE-2026-85581?

CVE-2026-85581 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-09-04.

How severe is CVE-2026-85581?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Siyuan-Note Siyuan

CVE-2026-85581

SiYuan before v3.8.2 contains a denial of service vulnerability in the unauthenticated /api/system/uiproc endpoint that accepts and retains attacker-controlled process identifiers without size limits or authentication. Attackers can send repeated requests with unique identifiers to exhaust process memory and degrade service availability.

Published 2026-09-04 · last modified 2026-09-10.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.3th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.006 · change: +0.003

Affected products

Siyuan-Note Siyuan

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/siyuan-note/siyuan/security/advisories/GHSA-wv96-wmf5-xvj2 (vendor-advisory)
www.vulncheck.com/advisories/siyuan-before-3.8.2-denial-of-service-via-unauthen… (third-party-advisory)

Frequently asked questions

What is CVE-2026-85581?: CVE-2026-85581 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-09-04.
How severe is CVE-2026-85581?: High severity. CVSS v3 base score is 7.5 out of 10.