XSS in Seafile Server
CVE-2026-30587
Multiple Stored XSS vulnerabilities exist in Seafile Server version 13.0.15,13.0.16-pro,12.0.14 and prior and fixed in 13.0.17, 13.0.17-pro, and 12.0.20-pro, via the Seadoc (sdoc) editor. The application fails to properly sanitize WebSocket messages regarding document structure updates. This allows authenticated remote attackers to inject malicious JavaScript payloads via the src attribute of embedded Excalidraw whiteboards or the href attribute of anchor tags
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.005 (37.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.1% 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: 0.005 · change: +0.002
Affected products
- Seafile Server — versions 13.0.15, 13.0.16
Weakness classification (CWE)
References
- gist.github.com/gabdevele/1b7e30ab367b26042fa32f45aa12ce2f (Exploit, Third Party Advisory)
- manual.seafile.com/13.0/changelog/server-changelog/ (Release Notes)
- manual.seafile.com/13.0/changelog/changelog-for-seafile-professional-server/ (Release Notes)
- manual.seafile.com/12.0/changelog/changelog-for-seafile-professional-server/ (Release Notes)
- github.com/haiwen/seahub/commit/4c5301747bdb84c64b2f2b3230417df2d1cc8987 (Patch)
- github.com/haiwen/seadoc-editor/commit/8fa988aaede072b2ae073d1b2edcb2fc691423b2 (Patch)
Frequently asked questions
- What is CVE-2026-30587?
- CVE-2026-30587 is a high-severity vulnerability in Seafile Server, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-03-25.
- How severe is CVE-2026-30587?
- High severity. CVSS v3 base score is 8.7 out of 10.