CVE-2026-25992

File Read Interface Case Bypass Vulnerability

Vulnerability Name

File Read Interface Case Bypass Vulnerability

Overview

The /api/file/getFile endpoint uses case-sensitive string equality checks to block access to sensitive files.
On case-insensitive file systems such as Windows, attackers can bypass restrictions using mixed-case paths
and read protected configuration files.

Trigger Conditions

• Running on a case-insensitive file system.
• The caller can access /api/file/getFile (via CheckAuth or Token injection in published services).

PoC (Generic Example)

After enabling publication:

Request:

POST /api/file/getFile
Content-Type: application/json

{"path":"cOnf/conf.json"}

Expected Result:

• Successfully return the content of the configuration file.

Root Cause

Path comparison uses strict case-sensitive string matching, without case normalization or identical file validation.

Fix Recommendations

• Normalize path casing before comparison (Windows/macOS).
• Use file-level comparison methods such as os.SameFile.
• Apply blacklist validation on sensitive paths after case normalization.

Notes

• Environment identifiers and sensitive information have been removed.

Solution Commit

399a38893e8719968ea2511e177bb53e09973fa6

• Read sensitive information in configuration files (e.g., access codes, API Tokens, sync configurations, etc.).
• Remotely exploitable directly when the service is published without authentication.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-25992 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Kodem intelligence

1. What is CVE-2026-25992? CVE-2026-25992 is a high-severity path traversal vulnerability in github.com/siyuan-note/siyuan/kernel (go), affecting versions <= 0.0.0-20260126094835-d5d10dd41b0c. No fixed version is listed yet. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-25992? CVE-2026-25992 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/siyuan-note/siyuan/kernel are affected by CVE-2026-25992? github.com/siyuan-note/siyuan/kernel (go) versions <= 0.0.0-20260126094835-d5d10dd41b0c is affected.
4. Is there a fix for CVE-2026-25992? No fixed version is listed for CVE-2026-25992 yet. Monitor the advisory for updates and apply mitigations in the interim.
5. Is CVE-2026-25992 exploitable, and should I be worried? Whether CVE-2026-25992 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-25992 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-25992? No fixed version is listed yet. In the interim: Resolve the canonical path after applying any user-supplied input, and verify it remains within the intended directory before accessing it.