{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2026-33555", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-04-13T16:22:13.958Z", "dateReserved": "2026-03-22T00:00:00.000Z", "datePublished": "2026-04-13T00:00:00.000Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "HAProxy", "vendor": "HAProxy", "versions": [{"lessThan": "3.3.6", "status": "affected", "version": "2.6", "versionType": "custom"}]}], "descriptions": [{"lang": "en", "value": "An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggling. The earliest affected version is 2.6."}], "problemTypes": [{"descriptions": [{"cweId": "CWE-130", "description": "CWE-130 Improper Handling of Length Parameter Inconsistency", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-04-13T16:22:13.958Z"}, "references": [{"url": "https://www.haproxy.org"}, {"url": "https://www.haproxy.com/documentation/haproxy-aloha/changelog/"}, {"url": "https://github.com/haproxy/haproxy/commit/05a295441c621089ffa4318daf0dbca2dd756a84"}, {"url": "https://www.mail-archive.com/haproxy@formilux.org/msg46752.html"}], "x_generator": {"engine": "enrichogram 0.0.1"}, "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 4, "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N"}}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6", "versionEndExcluding": "3.3.6"}]}]}]}}, "dataVersion": "5.2"}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggling. The earliest affected version is 2.6."}], "id": "CVE-2026-33555", "lastModified": "2026-04-13T17:16:28.237", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.0, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "cve@mitre.org", "type": "Secondary"}]}, "published": "2026-04-13T17:16:28.237", "references": [{"source": "cve@mitre.org", "url": "https://github.com/haproxy/haproxy/commit/05a295441c621089ffa4318daf0dbca2dd756a84"}, {"source": "cve@mitre.org", "url": "https://www.haproxy.com/documentation/haproxy-aloha/changelog/"}, {"source": "cve@mitre.org", "url": "https://www.haproxy.org"}, {"source": "cve@mitre.org", "url": "https://www.mail-archive.com/haproxy@formilux.org/msg46752.html"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-130"}], "source": "cve@mitre.org", "type": "Primary"}]}

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