GHSA-GW25-M53R-QH88
Vulnerability from github – Published: 2026-09-03 14:56 – Updated: 2026-09-03 14:56Summary
SiYuan's /export/ file handler was hardened against export disclosure (issue #12213) by adding an
IsSubPath(exportBaseDir, fullPath) check and an IsSensitivePath() check in commit bb481e1. These guards
were added only to the main branch of the handler. The handler begins with a short-circuit branch:
if strings.HasPrefix(c.Request.URL.Path, "/export/temp/") {
c.File(filepath.Join(util.TempDir, c.Request.URL.Path))
return
}
This branch joins the broader util.TempDir with the raw, percent-decoded request path and serves it with
neither IsSubPath nor IsSensitivePath. An authenticated request to
/export/temp/%2e%2e/.../etc/passwd traverses out of TempDir and reads arbitrary files - exactly the
sensitive-file disclosure the patch intended to prevent. Present in the latest master.
Affected
- From commit
bb481e1(the hardening) through the latest master. - Requires SiYuan access authorization (
model.CheckAuth) - but the patch's stated goal is to deny sensitive-file export even to authorized callers.
Root cause
kernel/server/serve.go serveExport(): the main branch has IsSubPath + IsSensitivePath; the
/export/temp/ short-circuit branch (above it) has neither and uses util.TempDir as its root.
c.Request.URL.Path is percent-decoded by net/http, so %2e%2e becomes .. and filepath.Join collapses it.
Incomplete-fix lineage
- Export disclosure (issue #12213; CVE-2026-30869) -> fix
bb481e1/d68bd5a(GHSA-6865-qjcf-286f): guards on the main branch +IsSensitivePathextended to*.db/*.log. - Follow-up CVE-2026-41894 (GHSA-hjh7-r5w8-5872) in the same
/exportpath family. - The
/export/temp/short-circuit branch was never covered by the guards (this report).
Proof of concept (benign)
- Authenticate (access auth code).
GET /export/<sensitive>(main branch) -> 401/403 (guards work).GET /export/temp/%2e%2e/%2e%2e/.../tmp/<planted-marker>(or/etc/hostname) -> 200 + file content, demonstrating the unguarded traversal. The PoC reads only a planted marker //etc/hostname; no credentials.
Impact
Authenticated arbitrary file read bypassing the sensitive-file protection: /etc/passwd, ~/.ssh/*, SiYuan
*.db workspace data, *.log.
Remediation
- Apply
IsSubPath+IsSensitivePathto the/export/temp/branch (or restrict its root toTempDir/tempwith anIsSubPathcheck). filepath.Cleanthe request path and reject...- Merge both branches into one guarded file-serving function.
References
- Hardening advisory: https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6865-qjcf-286f (commit d68bd5a); issue #12213.
- CVE chain: CVE-2026-30869 -> CVE-2026-41894 (GHSA-hjh7-r5w8-5872).
- serve.go guards commit: https://github.com/siyuan-note/siyuan/commit/bb481e1290c4a34255652ede85a546504505d2a7
- Residual source (master):
kernel/server/serve.goserveExport()lines 308-312.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/siyuan-note/siyuan/kernel"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20260510110132-b763d787d1f2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-03T14:56:31Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "## Summary\nSiYuan\u0027s `/export/` file handler was hardened against export disclosure (issue #12213) by adding an\n`IsSubPath(exportBaseDir, fullPath)` check and an `IsSensitivePath()` check in commit `bb481e1`. These guards\nwere added only to the main branch of the handler. The handler begins with a short-circuit branch:\n```go\nif strings.HasPrefix(c.Request.URL.Path, \"/export/temp/\") {\n c.File(filepath.Join(util.TempDir, c.Request.URL.Path))\n return\n}\n```\nThis branch joins the **broader** `util.TempDir` with the raw, percent-decoded request path and serves it with\n**neither** `IsSubPath` **nor** `IsSensitivePath`. An authenticated request to\n`/export/temp/%2e%2e/.../etc/passwd` traverses out of `TempDir` and reads arbitrary files - exactly the\nsensitive-file disclosure the patch intended to prevent. Present in the latest master.\n\n## Affected\n- From commit `bb481e1` (the hardening) through the latest master.\n- Requires SiYuan access authorization (`model.CheckAuth`) - but the patch\u0027s stated goal is to deny sensitive-file\n export even to authorized callers.\n\n## Root cause\n`kernel/server/serve.go` `serveExport()`: the main branch has `IsSubPath` + `IsSensitivePath`; the\n`/export/temp/` short-circuit branch (above it) has neither and uses `util.TempDir` as its root.\n`c.Request.URL.Path` is percent-decoded by net/http, so `%2e%2e` becomes `..` and `filepath.Join` collapses it.\n\n## Incomplete-fix lineage\n- Export disclosure (issue #12213; CVE-2026-30869) -\u003e fix `bb481e1` / `d68bd5a` (GHSA-6865-qjcf-286f): guards on\n the main branch + `IsSensitivePath` extended to `*.db`/`*.log`.\n- Follow-up CVE-2026-41894 (GHSA-hjh7-r5w8-5872) in the same `/export` path family.\n- The `/export/temp/` short-circuit branch was never covered by the guards (this report).\n\n## Proof of concept (benign)\n1. Authenticate (access auth code).\n2. `GET /export/\u003csensitive\u003e` (main branch) -\u003e 401/403 (guards work).\n3. `GET /export/temp/%2e%2e/%2e%2e/.../tmp/\u003cplanted-marker\u003e` (or `/etc/hostname`) -\u003e 200 + file content,\n demonstrating the unguarded traversal. The PoC reads only a planted marker / `/etc/hostname`; no credentials.\n\n## Impact\nAuthenticated arbitrary file read bypassing the sensitive-file protection: `/etc/passwd`, `~/.ssh/*`, SiYuan\n`*.db` workspace data, `*.log`. \n\n## Remediation\n- Apply `IsSubPath` + `IsSensitivePath` to the `/export/temp/` branch (or restrict its root to `TempDir/temp` with\n an `IsSubPath` check).\n- `filepath.Clean` the request path and reject `..`.\n- Merge both branches into one guarded file-serving function.\n\n## References\n- Hardening advisory: https://github.com/siyuan-note/siyuan/security/advisories/GHSA-6865-qjcf-286f (commit d68bd5a); issue #12213.\n- CVE chain: CVE-2026-30869 -\u003e CVE-2026-41894 (GHSA-hjh7-r5w8-5872).\n- serve.go guards commit: https://github.com/siyuan-note/siyuan/commit/bb481e1290c4a34255652ede85a546504505d2a7\n- Residual source (master): `kernel/server/serve.go` `serveExport()` lines 308-312.",
"id": "GHSA-gw25-m53r-qh88",
"modified": "2026-09-03T14:56:31Z",
"published": "2026-09-03T14:56:31Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-gw25-m53r-qh88"
},
{
"type": "WEB",
"url": "https://github.com/siyuan-note/siyuan/commit/b763d787d1f2b862c577049e4ee147c5857fe413"
},
{
"type": "PACKAGE",
"url": "https://github.com/siyuan-note/siyuan"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "SiYuan: path traversal via /export/temp/ short-circuit branch (incomplete fix for the export-disclosure hardening, GHSA-6865-qjcf-286f)"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.