Security readout for executives and security teams
Plain-English summary
SiYuan versions before 3.5.4 can reflect unsafe user-supplied text into an SVG image endpoint. If a user is tricked into opening a crafted link, script could run in the browser context. The vendor rates this low severity, and the issue is patched in 3.5.4.
Executive priority
Treat as a routine but prompt update for affected SiYuan users. The business risk is mainly browser-side script execution after user interaction, not direct server compromise. Prioritize upgrades where SiYuan is reachable by untrusted users or used with sensitive knowledge content.
Technical view
CVE-2026-23847 is a reflected XSS in SiYuan’s /api/icon/getDynamicIcon endpoint for dynamic text icons. The content parameter is inserted into an SVG <text> element without XML escaping. Because the response is image/svg+xml, malformed SVG content can alter markup and execute script. Affected versions are <3.5.4.
Likely exposure
Exposure is limited to SiYuan deployments or users running versions before 3.5.4. Exploitation requires user interaction, such as opening a crafted link. Internet exposure of the SiYuan service would increase practical risk, but the sources do not provide deployment prevalence.
Exploitation context
The CVSS vector indicates network access, low complexity, no privileges, and required user interaction. The CVE is not listed as KEV in the provided bundle, and no cited source states active exploitation. Public advisory, issue, and patch details are available.
Researcher notes
The root cause is missing XML escaping before embedding user-controlled content into SVG text output. The fixed version is identified as 3.5.4, with a linked commit. Sources do not provide evidence of active exploitation beyond public disclosure and patch availability.
Mitigation direction
- Upgrade SiYuan to version 3.5.4 or later.
- Review vendor advisory GHSA-w836-5gpm-7r93 for current guidance.
- Restrict access to SiYuan services where remote access is unnecessary.
- Avoid opening untrusted SiYuan links until upgraded.
Validation and detection
- Inventory SiYuan installations and confirm installed versions.
- Flag any SiYuan version earlier than 3.5.4 as affected.
- Confirm the vendor patch is present after upgrade.
- Review access logs for unusual requests to /api/icon/getDynamicIcon.
- Perform only safe, non-executing validation in a controlled environment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-23847 mapping review
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Open ATT&CK lookup- Severity
- Low
- CVSS
- 2.1 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
2.1LowVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:P
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-w836-5gpm-7r93CVE reference · x_refsource_CONFIRM
- https://github.com/siyuan-note/siyuan/issues/16844CVE reference · x_refsource_MISC
- https://github.com/siyuan-note/siyuan/commit/5c0cc375b47567e15edd2119066b09bb0aa18777CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.