Dashboard / CVE-2026-126265

CVE-2026-126265

CRITICAL
INFO Priority: 0.03 BB Relevance: 68/100
Published: 2026-11-13 Modified: 2026-11-13 First seen: 2026-11-13 Status: active

Attack Surface

Network No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: X
AT: Present
VC: High
VI: High
VA: None

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
siyuan-note siyuan 2.1.0 < 3.8.9

References & Advisories (2)

Bug Bounty Relevance

68 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

9.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.36%
Raw Score 0.003560
Percentile 29.8%
Date 2026-11-13

Intelligence Sources

mitre ref →
nvd ref →

External Links