{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58055","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-06-28T00:55:25.426Z","datePublished":"2026-06-28T01:32:57.163Z","dateUpdated":"2026-06-29T13:51:59.891Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-06-28T01:32:57.163Z"},"datePublic":"2026-06-26T00:00:00.000Z","title":"nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')","cweId":"CWE-444","type":"CWE"}]}],"affected":[{"vendor":"nghttp2","product":"nghttp2","defaultStatus":"affected","versions":[{"version":"0","status":"affected","versionType":"semver","lessThanOrEqual":"1.69.0"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:nghttp2:nghttp2:*:*:*:*:*:*:*:*","versionEndIncluding":"1.69.0"}]}]}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":6.3,"baseSeverity":"MEDIUM"}}],"references":[{"url":"https://github.com/bikini/exploitarium/tree/main/nghttp2-nghttpx-upgrade-queue-poison-poc","name":"Proof of Concept","tags":["exploit","third-party-advisory"]},{"url":"https://github.com/nghttp2/nghttp2/commit/ab28105c4a0197da24f8bfc414bc116055249e1e","name":"Fix commit (master)","tags":["patch"]},{"name":"VulnCheck Advisory: nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/nghttp2-nghttpx-http-request-response-smuggling-via-upgrade-request-with-content-length"}],"credits":[{"lang":"en","value":"ashdfrkl","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-29T13:51:50.981193Z","id":"CVE-2026-58055","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-29T13:51:59.891Z"}}]}}