CVE-2026-100636

validatedZero produced an exploit or a check.

GHSA-jf98-m24w-gm9m ↗EUVD-2026-87730 ↗

check availableZero validated a working check for it.not proven exploitableZero has a detection check, but hasn't produced a full working exploit yet.
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).−16dkevAttacks confirmed in the real world.
go:github.com/siyuan-note/siyuan <= 3.8.3
fixed in v3.8.4
CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
ETK-2026-266, permanent identifier
pkg:golang/github.com/siyuan-note/siyuan
+7.2dTTV
26mAI analysisAnalysis: how long the AI spent reversing this signal.
Check if you are vulnerable
timeline
0 = trigger signal
public poc−16dtrigger signal (cve.org) +0dcheck available+7.2dagent stopped
−10d
−5d
0
+5d
+10d

description

SiYuan versions before 3.8.4 allow an authenticated administrator to use the exportBrowserHTML endpoint to write attacker-controlled HTML to index.html outside the intended export directory. Exploitation requires administrator credentials and a pre-existing destination directory writable by the SiYuan kernel process; affected deployments may be exposed even when configured read-only.

mitigation

Upgrade SiYuan to v3.8.4 or later. Until upgraded, restrict administrator API access and prevent untrusted users from obtaining administrator credentials.

fixed in v3.8.4

check
available
exploit
no
automationDeterministic: a check that runs on its own, the same request on every target. Contextual: an agentic technique that needs to be applied per target, for bugs that depend on contextual flows.
deterministic
auth requiredWhether an attacker needs an account first, based on the CVSS vector's Privileges Required.
yes, high privileges
EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
0.54%44th percentile
agent run time
26m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-09-26 13:23Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
−16d
Δ to kevAttacks confirmed in the real world.
–

outcome

Check only, differential: the check fires on the vulnerable build and is silent on the patched one.

source signals

Public signals that triggered or updated the pipeline. These are inputs for the deltas above.

  1. 2026-09-26 13:23Z
  2. 2026-09-26 13:23Z
  3. 2026-09-26 13:23Z

this entry in the feed

GET /api/v1/feed/CVE-2026-100636

{
  "etk_id": "ETK-2026-266",
  "cve_id": "CVE-2026-100636",
  "display_id": "CVE-2026-100636",
  "ghsa_id": "GHSA-jf98-m24w-gm9m",
  "euvd_id": "EUVD-2026-87730",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Path traversal file write in SiYuan exportBrowserHTML",
  "summary": "SiYuan versions before 3.8.4 allow an authenticated administrator to use the exportBrowserHTML endpoint to write attacker-controlled HTML to index.html outside the intended export directory. Exploitation requires administrator credentials and a pre-existing destination directory writable by the SiYuan kernel process; affected deployments may be exposed even when configured read-only.",
  "mitigation": "Upgrade SiYuan to v3.8.4 or later. Until upgraded, restrict administrator API access and prevent untrusted users from obtaining administrator credentials.",
  "vendor": "go",
  "product": "go:github.com/siyuan-note/siyuan",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        "<= 3.8.3"
      ],
      "ecosystem": "go",
      "fixed_versions": [
        "v3.8.4"
      ],
      "package_name": "github.com/siyuan-note/siyuan",
      "purl": "pkg:golang/github.com/siyuan-note/siyuan"
    }
  ],
  "cwes": [
    22
  ],
  "cvss_score": 7.6,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L",
  "epss_score": 0.0054,
  "epss_percentile": 0.4457,
  "epss_asof": "2026-10-20",
  "automation": "deterministic",
  "check": true,
  "check_confidence_basis": "differential",
  "exploit": false,
  "pipeline_minutes": 26.426225483333333,
  "t0_at": "2026-09-26T13:23:10.528000+00:00",
  "signals": {
    "check": {
      "at": "2026-10-03T19:00:58.333893+00:00",
      "days": 7.234581086724537,
      "is_lower_bound": false,
      "measured_at": "2026-09-26T13:23:10.528000+00:00",
      "url": null
    },
    "public_poc": {
      "at": "2026-09-10T15:05:17+00:00",
      "days": -15.92909175925926,
      "is_lower_bound": false,
      "measured_at": "2026-09-26T13:23:10.528000+00:00",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jf98-m24w-gm9m"
    },
    "trigger_signal": {
      "at": "2026-09-26T13:23:10.528000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-09-26T13:23:10.528000+00:00",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jf98-m24w-gm9m"
    }
  }
}

published 2026-10-01 18:06Z
last change 2026-10-21 04:45Z

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