# Echo has CSRF Protection Bypass via MethodOverride Rewriting POST to Safe Method Advisory record · `GHSA-r7w9-592q-9vg4` - **Identifiers:** `GHSA-r7w9-592q-9vg4` · `CVE-2026-118266` · `GO-2026-6877` - **State:** Confirmed - **Severity:** CVSS 5.3 Medium - **Critical:** No - **Weakness (CWE):** [CWE-352](https://cwe.mitre.org/data/definitions/352.html) - **Tags:** [Cross-site request forgery (CSRF)](https://agentprime.io/advisories/tag/csrf.md) - **Published:** 28 Oct 2026 - **Updated:** 5 Nov 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 28 Oct 2026, 19:53 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `github.com/labstack/echo/v5` (Go): affected `>=5.0.0, <5.4.0`; fixed in `5.4.0` - `github.com/labstack/echo/v4` (Go): affected `<4.16.0`; fixed in `4.16.0` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Echo v5 versions from 5.0.0 before 5.4.0 and Echo v4 versions before 4.16.0 are affected. When MethodOverride is registered with e.Use() ahead of CSRF, a POST request can be rewritten to a safe method such as GET, which causes CSRF to skip token validation and lets state-changing POST handlers run without a CSRF check. Upgrade github.com/labstack/echo/v5 to 5.4.0 or github.com/labstack/echo/v4 to 4.16.0. As a workaround, register MethodOverride with e.Pre() or register CSRF before MethodOverride. Written 1 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 5.3 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0016, the 5th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 28 Oct 2026, 19:21 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-118266) - 28 Oct 2026, 20:17 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-118266) - 31 Oct 2026, 14:11 UTC: First seen by agentprime - 31 Oct 2026, 14:11 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-r7w9-592q-9vg4) ## Sources - [GitHub Advisory Database: GHSA-r7w9-592q-9vg4](https://github.com/advisories/GHSA-r7w9-592q-9vg4) - [OSV: GHSA-r7w9-592q-9vg4](https://osv.dev/vulnerability/GHSA-r7w9-592q-9vg4) - - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .