CVE-2026-55603

{"id": "CVE-2026-55603", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55603", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-23T12:20:45.426994Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 4.7, "exploitabilityScore": 2.2}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "chimurai", "product": "http-proxy-middleware", "versions": [{"status": "affected", "version": ">= 3.0.4, < 3.0.7"}, {"status": "affected", "version": ">= 4.0.0, < 4.1.1"}]}]}], "published": "2026-06-22T21:16:26.033", "references": [{"url": "https://github.com/chimurai/http-proxy-middleware/security/advisories/GHSA-gcq2-9pq2-cxqm", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/chimurai/http-proxy-middleware/security/advisories/GHSA-gcq2-9pq2-cxqm", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-93"}]}], "descriptions": [{"lang": "en", "value": "http-proxy-middleware is node.js http-proxy middleware. From 3.0.4 until 3.0.7 and 4.1.1, fixRequestBody() is the library's documented helper for re-emitting a request body that was already consumed by a body parser. When the outgoing Content-Type is multipart/form-data, it rebuilds the body with handlerFormDataBodyData(), which interpolates each req.body key and value directly into the multipart wire format without neutralizing CR/LF. A \\r\\n inside a value (or key) lets an attacker close the current part and inject an entirely new form part. Because the proxy's own body parser saw a single opaque value, any gateway-side policy or validation performed on req.body is evaluated against a different set of fields than the upstream backend ultimately parses a request/parameter desynchronization across the trust boundary. This vulnerability is fixed in 3.0.7 and 4.1.1."}], "lastModified": "2026-06-24T16:44:28.870", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:chimurai:http-proxy-middleware:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8281B19B-A543-4996-B6E0-3A43AD44585B", "versionEndExcluding": "3.0.7", "versionStartIncluding": "3.0.4"}, {"criteria": "cpe:2.3:a:chimurai:http-proxy-middleware:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D9D194C5-E95E-410C-BFB4-A36DCC12F656", "versionEndExcluding": "4.1.1", "versionStartIncluding": "4.0.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}