{"id":"GHSA-h53f-rm2w-w7rg","title":"Echo: X-Real-IP extractor trusts the header value instead of the sending peer","summary":"Echo: X-Real-IP extractor trusts the header value instead of the sending peer","severity":"medium","cvss":5.3,"cwe":["CWE-348"],"vendor":"labstack","product":"github.com/labstack/echo/v5","ecosystem":"go","affected":["github.com/labstack/echo/v5 >= 5.0.0, < 5.4.1"],"patched":["github.com/labstack/echo/v5 5.4.1"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T20:50:27Z","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-h53f-rm2w-w7rg","references":[{"url":"https://github.com/labstack/echo/security/advisories/GHSA-h53f-rm2w-w7rg"},{"url":"https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec"},{"url":"https://github.com/labstack/echo/releases/tag/v5.4.1"},{"url":"https://github.com/advisories/GHSA-h53f-rm2w-w7rg"}],"tags":["ghsa","go"],"ingestedAt":"2026-10-23T21:38:13.041Z","slug":"GHSA-h53f-rm2w-w7rg","body":"## Overview\n\n## Impact\n\nIn Echo v5, `ExtractIPFromRealIPHeader` checked whether the address supplied in `X-Real-IP` belonged to a trusted range instead of checking the address of the direct network peer. An untrusted client could therefore supply a loopback or private address and have it returned by `c.RealIP()` with the extractor's default trust options.\n\nApplications using this extractor for IP allowlists, IP-based rate limiting, audit logs or forwarding headers could accept a spoofed client identity. Exploitation requires that the attacker can reach Echo directly or that an intervening proxy passes through the attacker's `X-Real-IP` value. Applications using the default direct IP extractor are unaffected. Echo v4 is unaffected by this v5 regression.\n\n## Affected versions and patch\n\nAll v5 releases from v5.0.0 through v5.4.0 are affected. Upgrade to [v5.4.1](https://github.com/labstack/echo/releases/tag/v5.4.1).\n\nThe patch validates the direct peer before accepting a syntactically valid `X-Real-IP` value, restoring the v4 trust model. [Fix commit](https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec).\n\n## Workarounds\n\nUse `ExtractIPDirect` until upgrading, or ensure that only trusted proxies can reach Echo and that they replace client-supplied forwarding headers. Configure trusted proxy ranges narrowly for the deployment.\n\n## Credits\n\nReported and patched by @rm-Umar. @Duodum independently reported the same issue in GHSA-c3r7-8j36-7mx8, which is tracked as a duplicate of this advisory.\n\n## Affected packages\n\n- `github.com/labstack/echo/v5 >= 5.0.0, < 5.4.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/labstack/echo/v5 5.4.1`","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}