Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:LSummary
CVE-2026-30869 is a critical-severity Path Traversal (CWE-22) vulnerability in B3Log Siyuan. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 39% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-30869 is a path traversal vulnerability (CWE-22) affecting SiYuan, a personal knowledge management system, in versions prior to 3.5.10. The issue resides in the /export endpoint, which fails to properly sanitize inputs, allowing attackers to exploit double-encoded traversal sequences such as "../" to read arbitrary files from the server filesystem. This includes sensitive configuration files like conf/conf.json, which stores critical secrets such as the API token, cookie signing key, and workspace access authentication code. The vulnerability carries a CVSS v3.1 base score of 9.3 (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L), indicating high severity due to its network accessibility, low complexity, and lack of prerequisites.
Any unauthenticated remote attacker can exploit this vulnerability by sending crafted requests to the /export endpoint. Successful exploitation enables the disclosure of sensitive files and secrets, potentially granting administrative access to the SiYuan kernel API. In certain deployment configurations, these leaked credentials could be chained with other flaws to achieve remote code execution (RCE), amplifying the impact beyond mere information disclosure.
The vulnerability is fixed in SiYuan version 3.5.10, as detailed in the GitHub Security Advisory GHSA-2h2p-mvfx-868w. Security practitioners should upgrade to the patched version immediately and review access logs for exploitation attempts involving double-encoded path traversal payloads.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10414
Vulnerability Data
SiYuan is a personal knowledge management system. Prior to 3.5.10, a path traversal vulnerability in the /export endpoint allows an attacker to read arbitrary files from the server filesystem. By exploiting double‑encoded traversal sequences, an attacker can access sensitive files…
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such as conf/conf.json, which contains secrets including the API token, cookie signing key, and workspace access authentication code. Leaking these secrets may enable administrative access to the SiYuan kernel API, and in certain deployment scenarios could potentially be chained into remote code execution (RCE). This vulnerability is fixed in 3.5.10.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.