{"id":"CVE-2026-118262","summary":"Echo: WebSocket proxy can retain connections and handlers after client disconnect","details":"Echo is a Go web framework. From 4.15.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware can retain a handler, copy goroutines, and network connections after a WebSocket client disconnects when the upstream keeps its connection open. The raw proxy waits for both copy directions without reliably closing the peer connection when one direction ends, including when a rejected upgrade response uses HTTP keep-alive. Repeated connections can accumulate resources and cause denial of service, depending on proxy-route accessibility, upstream behavior, and connection deadlines. This issue is fixed in 4.16.1 and 5.4.1.","aliases":["GHSA-9969-6676-49h5"],"modified":"2026-10-29T10:45:54.368000866Z","published":"2026-10-28T19:00:12.315Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-772"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118262.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118262.json"},{"type":"FIX","url":"https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec"},{"type":"FIX","url":"https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f"},{"type":"WEB","url":"https://github.com/labstack/echo/releases/tag/v4.16.1"},{"type":"WEB","url":"https://github.com/labstack/echo/releases/tag/v5.4.1"},{"type":"ADVISORY","url":"https://github.com/labstack/echo/security/advisories/GHSA-9969-6676-49h5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118262"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/labstack/echo","events":[{"introduced":"482bb46fe5c7eb7c9fd7bec7d3128433dea21bee"},{"fixed":"600b9855dfbcb22c7e643e43ce397d5248e882b2"},{"introduced":"9500f2745481e2dff1313e2e6734c488e80c13fb"},{"fixed":"a6a9673a54d2c719ceb32ce6a929d35483acfb2b"},{"fixed":"1855061e572ae9dab727c811d8382f266bfbaaec"},{"fixed":"3fb0ba7e17645bb65611e2a08875d0a2f65c421f"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StringRangeExpression","range":[{"introduced":"4.15.0"},{"fixed":"4.16.1"}]},{"range":[{"introduced":"5.0.0"},{"fixed":"5.4.1"}],"source":"AFFECTED_FIELD","strategy":"StringRangeExpression"},{"range":[{"fixed":"1855061e572ae9dab727c811d8382f266bfbaaec"}],"source":"REFERENCES_COMMIT"},{"range":[{"fixed":"3fb0ba7e17645bb65611e2a08875d0a2f65c421f"}],"source":"REFERENCES_COMMIT"},{"original_tag":"v4.16.1","range":[{"fixed":"600b9855dfbcb22c7e643e43ce397d5248e882b2"}],"source":"REFERENCES_TAG"},{"range":[{"fixed":"a6a9673a54d2c719ceb32ce6a929d35483acfb2b"}],"source":"REFERENCES_TAG","original_tag":"v5.4.1"}]}}],"versions":["v4.16.0","v5.4.0","v5.3.1","v5.3.0","v4.15.4","v5.2.1","v5.2.0","v4.15.3","v4.15.2","v5.1.1","v4.15.1","v5.1.0","v5.0.4","v4.15.0","v5.0.3","v5.0.2","v5.0.1","v5.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-118262.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}