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  4. CVE 2026 126265 siyuan 210 before 389 captcha bypass via stale
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Back to active CVEs
Critical · CVSS 9.1CVE-2026-126265

SiYuan 2.1.0 before 3.8.9 CAPTCHA Bypass via Stale Login CookieCVE-2026-126265

Answer in brief

CVE-2026-126265 records a Critical severity (CVSS 9.1) vulnerability in SiYuan 2.1.0 before 3.8.9 CAPTCHA Bypass via Stale Login Cookie. The current sources do not mark it as known exploited. The current feed maps siyuan-note/siyuan (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 13, 2026Updated Nov 13, 2026Source checked Nov 13, 2026First seen by HOL Nov 13, 2026Material review Nov 13, 2026
Upstream Advisory

Key facts

Risk
Critical · CVSS 9.1
Exploitation
Not marked as known exploited
Affected software
1 mapped package or product
Fix availability
Available

Why this deserves its current priority

CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps siyuan-note/siyuan (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
siyuan-note/siyuangeneric>=2.1.0 <3.8.93.8.9

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for siyuan-note/siyuan.
  2. 2Review the reported fix. Update siyuan-note/siyuan to 3.8.9 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Nov 13, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Nov 13, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Nov 13, 2026

Sources and claim methodology

  • GitHub security advisorygithub.com
  • Source referencevulncheck.com
Upstream source description

SiYuan 2.1.0 before 3.8.9 contains a flaw where the loginAuth CAPTCHA challenge lives in a signed client-side cookie, allowing reuse of a solved challenge. Attackers can replay the original signed siyuan cookie with distinct wrong access codes to brute-force the code and gain an administrator session.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • SiYuan before 3.8.9 Sensitive File Disclosure via /api/file/getFileSame siyuan-note/siyuan package
  • SiYuan from 3.6.0 before 3.8.9 Publish-Password Bypass via getDoc Regex KeywordsSame siyuan-note/siyuan package

Record context

Vulnerability class
Vulnerability
EPSS
Not reported
CWE IDs
CWE-307
Source
CVE List V5
Source checked
Nov 13, 2026
References
2 linked sources
Open source record