{"cve":"CVE-2026-31809","nvd":{"published":"2026-03-10T21:16:50.337","modified":"2026-06-17T10:34:30.170","status":"Analyzed","description":"SiYuan is a personal knowledge management system. Prior to 3.5.10, SiYuan's SVG sanitizer (SanitizeSVG) checks href attributes for the javascript: prefix using strings.HasPrefix(). However, inserting ASCII tab (&#9;), newline (&#10;), or carriage return (&#13;) characters inside the javascript: string bypasses this prefix check. Browsers strip these characters per the WHATWG URL specification before parsing the URL scheme, so the JavaScript still executes. This allows an attacker to inject executable JavaScript into the unauthenticated /api/icon/getDynamicIcon endpoint, creating a reflected XSS. This is a second bypass of the fix for CVE-2026-29183 (fixed in v3.5.9). This vulnerability is fixed in 3.5.10.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":6.4},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["https://github.com/siyuan-note/siyuan/security/advisories/GHSA-pmc9-f5qr-2pcr"],"products":["b3log:siyuan"],"source":"nvd","synced_at":"2026-10-19T22:25:53.701907451+00:00"},"epss":{"cve":"CVE-2026-31809","score":0.00517,"percentile":0.43986,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-pmc9-f5qr-2pcr","url":"https://osv.dev/vulnerability/GHSA-pmc9-f5qr-2pcr","summary":"SiYuan has a SVG Sanitizer Bypass via Whitespace in `javascript:` URI — Unauthenticated XSS","modified":"2026-03-23T04:56:03.396482991Z","packages":[{"ecosystem":"Go","name":"github.com/siyuan-note/siyuan/kernel","purl":"pkg:golang/github.com/siyuan-note/siyuan/kernel","ranges":["<0.0.0-20260310025236-297bd526708f"],"fixed":["0.0.0-20260310025236-297bd526708f"]}]},{"id":"GO-2026-4669","url":"https://osv.dev/vulnerability/GO-2026-4669","summary":"SiYuan has a SVG Sanitizer Bypass via Whitespace in `javascript:` URI — Unauthenticated XSS in github.com/siyuan-note/siyuan/kernel","modified":"2026-03-23T04:52:52.467395Z","packages":[{"ecosystem":"Go","name":"github.com/siyuan-note/siyuan/kernel","purl":"pkg:golang/github.com/siyuan-note/siyuan/kernel","ranges":["<0.0.0-20260310025236-297bd526708f"],"fixed":["0.0.0-20260310025236-297bd526708f"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}