Summary
SiYuan: Tag labels from password-protected documents are returned to readers who have not entered the password
CVE: This vulnerability corresponds to CVE-2026-72792.
/api/tag/getTag filters its results for reader roles through FilterTagsByPublishIgnore, which checks only the visible publish tier. Documents that are published but password-protected pass that check, so a reader who has never entered a document's publish password receives every tag label used inside it, together with occurrence counts.
The project has already treated this exact tier mismatch as a vulnerability on a sibling path: commit 82e9ded42 ("Enforce publish access for graph nodes") moved the graph endpoint off the visible-only filter and onto a password-aware one. FilterTagsByPublishIgnore was not upgraded alongside it.
Details
| Item | Detail |
|---|---|
| Route | kernel/api/router.go:194 POST /api/tag/getTag → model.CheckAuth → getTag |
| Middleware | CheckAuth only: no CheckReadonly, no CheckAdminRole |
| Guard | Present but at the wrong tier: visible-only, no password check |
| Exposed | Every tag label (#label# text) and its occurrence count inside password-protected but visible documents |
The tier mismatch. For reader roles, getTag filters via:
publishIgnore := GetInvisiblePublishAccess(publishAccess)
tags = FilterTagsByPublishIgnore(publishIgnore, tags)
FilterTagsByPublishIgnore counts a label if CheckPathAccessableByPublishIgnore(span.Box, span.Path, publishIgnore) holds, then reads label := util.UnescapeHTML(span.Content).
CheckPathAccessableByPublishIgnore (kernel/model/publish_access.go:183) consults the invisible set only. It returns true for any visible document, including one carrying a publish password. The project's complete gate is checkBlockTreeAccessableByPublishAccess (kernel/model/publish_access.go:225), which ANDs that same visibility test with password == "" || CheckPublishAuthCookie(...). The tag filter implements the first half and omits the second.
The disclosed value is user-authored content, not a structural identifier: span.Content is the tag text an author wrote inside the document project codenames, personal names, client names, subject matter and the accompanying count reveals how heavily each appears.
Established as a defect by the project's own remediation. Commit 82e9ded42 replaced the graph endpoint's visible-only FilterGraphByPublishIgnore with a filter that additionally resolves the document's publish password and validates CheckPublishAuthCookie. The reasoning that motivated that change applies unchanged here: same input shape, same visible-only body, same class of leaked material. FilterTagsByPublishIgnore retains the pre-fix pattern.
Verified unfixed. At v3.7.4-alpha.1, getTag still calls FilterTagsByPublishIgnore, and that function's body still tests only CheckPathAccessableByPublishIgnore. No commit on the development branch touches kernel/api/tag.go or the tag filter (git log and git log -S both empty over that range).
Scope note on the remaining visible-only call sites. Two further consumers of the *ByPublishIgnore tier were reviewed and are not claimed as vulnerabilities in this report: listDocsByPath (kernel/model/filetree.go:1160), which exposes document titles and is plausibly intentional for navigation, and the identifier-only filter, which returns no authored content. They are noted because the visible-only tier is now a repeated source of defects, and an audit of every *ByPublishIgnore call site is the durable remedy rather than a third individual patch.
Proof of Concept
Precondition: publish mode enabled (default port 6808); a published document that carries a publish password and contains at least one tag; a reader session that has not authenticated to that document.
POST http://127.0.0.1:6808/api/tag/getTag
{}
→ 200
The returned tag tree includes labels sourced from the password-protected
document, with counts, despite the session holding no publish auth cookie
for it.
Differential check: request the document itself through a password-gated endpoint with the same session and observe that access is refused, while its tag labels remain present in the getTag response.
Impact
An anonymous reader in publish mode or any publish RoleReader enumerates the tag vocabulary of documents they are not authorized to open, along with usage counts. Tags are author-written free text, so this discloses subject matter, names and internal terminology from documents whose contents the publish password was configured to protect. Confidentiality-only.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-72792 has a CVSS score of 5.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260726002639-4515fa257cfa); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
Replace FilterTagsByPublishIgnore with a password-aware filter mirroring the one introduced in 82e9ded42 for graph nodes: resolve each span's document password via GetPathPasswordByPublishAccess and require CheckPublishAuthCookie before the label is counted, in addition to the existing visibility test. More durably, audit every remaining *ByPublishIgnore call site against checkBlockTreeAccessableByPublishAccess the visible-only tier has now produced this defect on at least two separate endpoints.
Frequently Asked Questions
- What is CVE-2026-72792? CVE-2026-72792 is a medium-severity incorrect authorization vulnerability in github.com/siyuan-note/siyuan/kernel (go), affecting versions < 0.0.0-20260726002639-4515fa257cfa. It is fixed in 0.0.0-20260726002639-4515fa257cfa. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2026-72792? CVE-2026-72792 has a CVSS score of 5.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/siyuan-note/siyuan/kernel are affected by CVE-2026-72792? github.com/siyuan-note/siyuan/kernel (go) versions < 0.0.0-20260726002639-4515fa257cfa is affected.
- Is there a fix for CVE-2026-72792? Yes. CVE-2026-72792 is fixed in 0.0.0-20260726002639-4515fa257cfa. Upgrade to this version or later.
- Is CVE-2026-72792 exploitable, and should I be worried? Whether CVE-2026-72792 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-72792 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-72792? Upgrade
github.com/siyuan-note/siyuan/kernelto 0.0.0-20260726002639-4515fa257cfa or later.