Skip to main content
Public proof of conceptFix available

CVE-2026-25766

A public proof of concept exists; no exploitation attested.

  • Published2026-02-19
  • Fixed in5.0.3
  • WeaknessCWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-02-1916:27CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-25766?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-25766?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Labstack echoversion to verify
BranchAffectedFixed in
5.0≥ 5.0.0, < 5.0.35.0.3

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As GitHub_M, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • labstack echo
    Affected
    • = >= 5.0.0, < 5.0.3no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-02-19

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • govulncheck-vulndbopenSUSE:Leap 16.0all versions · fixed in 0.0.20260723T184607-160000.1.1
  • govulncheck-vulndbopenSUSE:Leap 15.6all versions · fixed in 0.0.20260226T182644-150000.1.149.1

Full record on NVD

Fix

  1. Update Labstack echo to 5.0.3

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionpoc2026-02-19
  • OpenCVESSVC decisionpoc—
  • CNACVSS 3.15.3known since 2026-10-23
  • CNAweakness (CWE)CWE-22known since 2026-10-23
  • FIRST EPSSEPSS score0.4 %2026-11-03
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryMODERATE2026-02-17

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Published
2026-02-19
Last Modified
2026-06-17
NVD status
Analyzed
GitHub Advisory
GHSA-pgvm-wxw2-hrv9

Frequently asked questions

What is CVE-2026-25766?

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.

Is CVE-2026-25766 actively exploited?

A proof-of-concept exploit exists for CVE-2026-25766, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-25766?

CVE-2026-25766 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Running labstack/echo? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record