CVE-2026-118266
Echo: CSRF Protection Bypass via MethodOverride Rewriting POST to Safe Method
Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, Echo's MethodOverride middleware accepts a safe HTTP method as the override target for a POST request. When MethodOverride is registered before CSRF in the post-routing middleware chain, route selection retains the original state-changing POST handler but the override changes the method before CSRF evaluates it, causing both token validation and Sec-Fetch-Site checks to be skipped. A cross-site exploit requires an authenticated victim and an override value that a browser-submitted request can control, such as the form getter used by the advisory reproducer; the default X-HTTP-Method-Override header getter is not settable by a cross-site form. This issue is fixed in 4.16.0 and 5.4.0.
Fixes and workarounds
Fix
github.com/labstack/echo/v5 (Go): OSV reports a fixed version 5.4.0. Check the advisory for supported release branches.
Source: OSV GHSA-r7w9-592q-9vg4Fix
github.com/labstack/echo/v4 (Go): OSV reports a fixed version 4.16.0. Check the advisory for supported release branches.
Source: OSV GHSA-r7w9-592q-9vg4Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| echo labstack |
< 4.16.0 (affected) >= 5.0.0, < 5.4.0 (affected) |
CNA: GitHub_M |
github.com/labstack/echo/v5github.com/labstack/echo/v5
Go |
≥ 5.0.0; < 5.4.0 (affected, semver); OSV events: introduced 5.0.0; fixed 5.4.0Source events (semver)Other versions: unaffected |
OSV GHSA-r7w9-592q-9vg4 |
github.com/labstack/echo/v4github.com/labstack/echo/v4
Go |
≥ 0; < 4.16.0 (affected, semver); OSV events: introduced 0; fixed 4.16.0Source events (semver)Other versions: unaffected |
OSV GHSA-r7w9-592q-9vg4 |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N | CNA: GitHub_M |
Exploit evidence
- https://github.com/labstack/echo/security/advisories/GHSA-r7w9-592q-9vg4
exploit · ADP: CISA-ADP
References
- https://github.com/labstack/echo/security/advisories/GHSA-r7w9-592q-9vg4CNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/labstack/echo/commit/b838391e2eade87ae7e5a09d7bb5087bec271ec1CNA: GitHub_M · x_refsource_MISC
- https://github.com/labstack/echo/commit/fc410094b2f3415cf2bf5204082137b205bfd5afCNA: GitHub_M · x_refsource_MISC
- https://github.com/labstack/echo/releases/tag/v4.16.0CNA: GitHub_M · x_refsource_MISC
- https://github.com/labstack/echo/releases/tag/v5.4.0CNA: GitHub_M · x_refsource_MISC
- https://github.com/labstack/echo/security/advisories/GHSA-r7w9-592q-9vg4ADP: CISA-ADP · exploit
- https://github.com/advisories/GHSA-r7w9-592q-9vg4OSV / GitHub Security Advisories · advisory
- https://osv.dev/vulnerability/GHSA-r7w9-592q-9vg4OSV / GitHub Security Advisories · osv
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