{"id":"CVE-2026-58055","summary":"nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length","details":"nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.","modified":"2026-08-12T04:19:12.212363858Z","published":"2026-06-28T01:32:57.163Z","related":["CGA-833v-74cw-p36q","SUSE-SU-2026:22594-1","SUSE-SU-2026:22630-1","SUSE-SU-2026:22707-1","SUSE-SU-2026:22893-1","SUSE-SU-2026:2883-1","SUSE-SU-2026:3153-1","SUSE-SU-2026:3154-1","openSUSE-SU-2026:11156-1","openSUSE-SU-2026:21302-1"],"database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-444"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58055.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58055.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-58055"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/nghttp2-nghttpx-http-request-response-smuggling-via-upgrade-request-with-content-length"},{"type":"FIX","url":"https://github.com/nghttp2/nghttp2/commit/ab28105c4a0197da24f8bfc414bc116055249e1e"},{"type":"EVIDENCE","url":"https://github.com/bikini/exploitarium/tree/main/nghttp2-nghttpx-upgrade-queue-poison-poc"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nghttp2/nghttp2","events":[{"introduced":"0"},{"fixed":"ab28105c4a0197da24f8bfc414bc116055249e1e"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"1.69.0"}],"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:nghttp2:nghttp2:*:*:*:*:*:*:*:*"}}],"versions":["v1.69.0","v1.68.0","v1.67.0","v1.66.0","v1.65.0","v1.64.0","v1.63.0","v1.62.0","v1.61.0","v1.60.0","v1.59.0","v1.58.0","v1.57.0","v1.56.0","v1.55.0","v1.54.0","v1.53.0","v1.52.0","v1.51.0","v1.50.0","v1.49.0","v1.48.0","v1.47.0","v1.46.0","v1.45.0","v1.44.0","v1.43.0","v1.42.0","v1.41.0","v1.40.0","v1.39.0","v1.38.0","v1.37.0","v1.36.0","v1.35.0","v1.34.0","v1.33.0","v1.32.0","v1.31.0","v1.30.0","v1.29.0","v1.28.0","v1.27.0","v1.26.0","v1.25.0","v1.24.0","v1.23.0","v1.22.0","v1.21.0","v1.20.0","v1.19.0","v1.18.0","v1.17.0","v1.16.0","v1.15.0","v1.14.0","v1.13.0","v1.12.0","v1.11.0","v1.10.0","v1.9.1","v1.9.0","v1.8.0","v1.7.0","v1.6.0","v1.5.0","v1.4.0","v1.3.4","v1.3.3","v1.3.2","v1.3.1","v1.3.0","v1.2.1","v1.2.0","v1.1.2","v1.1.1","v1.1.0","v1.0.5","v1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0.0","v0.7.15","v0.7.14","v0.7.13","v0.7.12","v0.7.11","v0.7.10","v0.7.9","v0.7.8","v0.7.7","v0.7.6","v0.7.5","v0.7.4","v0.7.3","v0.7.2","v0.7.1","v0.7.0","v0.6.7","v0.6.6","v0.6.5","v0.6.4","v0.6.3","v0.6.2","v0.6.1","v0.6.0","v0.5.1","v0.5.0","v0.4.1","v0.4.0","v0.3.1","v0.3.0","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-58055.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N"}]}