CVE-2026-25766
Echo has a Windows path traversal via backslash in middleware.Static default filesystem
Description
Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo’s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\` as a path separator, so `..\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\` as a path separator and resolves `..\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue.
INFO
Published Date :
Feb. 19, 2026, 4:27 p.m.
Last Modified :
Feb. 23, 2026, 8:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Echo to version 5.0.3 or later.
- Verify static file serving configuration.
- Restrict access to static files.
Public PoC/Exploit Available at Github
CVE-2026-25766 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-25766.
| URL | Resource |
|---|---|
| https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1 | Patch |
| https://github.com/labstack/echo/pull/2891 | Issue Tracking Patch |
| https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-25766 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-25766
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
# مستودع asrar-mared هذا هو المستودع الرئيسي لمجموعة **المارد الرقمي**، نقطة التحكم المركزية التي تجمع كل المشاريع والميول التقنية تحت راية واحدة. يمثل الأساس الذي تُبنى عليه الفروع الأخرى، ويُدار منه كل شيء من تنظيم الكود إلى إدارة المجتمع. للاطلاع على المستودع: [asrar-mared](https://github.com/asrar-mared)
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Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-25766 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-25766 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 23, 2026
Action Type Old Value New Value Added CPE Configuration AND OR *cpe:2.3:a:labstack:echo:*:*:*:*:*:go:*:* versions from (including) 5.0.0 up to (excluding) 5.0.3 OR cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Added Reference Type GitHub, Inc.: https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/labstack/echo/pull/2891 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9 Types: Exploit, Vendor Advisory -
New CVE Received by [email protected]
Feb. 19, 2026
Action Type Old Value New Value Added Description Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo’s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\` as a path separator, so `..\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\` as a path separator and resolves `..\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-22 Added Reference https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1 Added Reference https://github.com/labstack/echo/pull/2891 Added Reference https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9