CSRF in Labstack Echo
CVE-2026-118266
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.
Vulnerability class: CSRF (Cross-Site Request Forgery)
Published .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Labstack Echo — versions < 4.16.0, >= 5.0.0, < 5.4.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-118266?
- CVE-2026-118266 is a medium-severity vulnerability in Labstack Echo, classified under Cross-Site Request Forgery (CSRF). CVSS score: 5.3/10. Published 2026-10-28.
- How severe is CVE-2026-118266?
- Medium severity. CVSS v3 base score is 5.3 out of 10.