CVE-2026-55614 (GCVE-0-2026-55614)

Vulnerability from cvelistv5 – Published: 2026-10-30 22:01 – Updated: 2026-10-30 22:01
VLAI
Title
uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching
Summary
uhttpd is a small HTTP server. In unpatched repository snapshots, `client_parse_header()` in `client.c` lowercases header names but compares the `Transfer-Encoding` value to `chunked` using case-sensitive `strcmp`. A mixed-case transfer-coding token is accepted without enabling `r->transfer_chunked`, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the `chunked` POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
Severity
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7886 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
openwrt uhttpd Affected: >= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, < ae015e099986ceace44975cb69629841a2d58d37
Affected: >= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, < 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "uhttpd",
          "vendor": "openwrt",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, \u003c ae015e099986ceace44975cb69629841a2d58d37"
            },
            {
              "status": "affected",
              "version": "\u003e= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, \u003c 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "uhttpd is a small HTTP server. In unpatched repository snapshots, `client_parse_header()` in `client.c` lowercases header names but compares the `Transfer-Encoding` value to `chunked` using case-sensitive `strcmp`. A mixed-case transfer-coding token is accepted without enabling `r-\u003etransfer_chunked`, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the `chunked` POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-30T22:01:54.750Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/openwrt/uhttpd/security/advisories/GHSA-mcfg-c4r7-pjpf",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/openwrt/uhttpd/security/advisories/GHSA-mcfg-c4r7-pjpf"
        },
        {
          "name": "https://github.com/openwrt/uhttpd/commit/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/openwrt/uhttpd/commit/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837"
        },
        {
          "name": "https://github.com/openwrt/uhttpd/commit/ae015e099986ceace44975cb69629841a2d58d37",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/openwrt/uhttpd/commit/ae015e099986ceace44975cb69629841a2d58d37"
        }
      ],
      "source": {
        "advisory": "GHSA-mcfg-c4r7-pjpf",
        "discovery": "UNKNOWN"
      },
      "title": "uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55614",
    "datePublished": "2026-10-30T22:01:54.750Z",
    "dateReserved": "2026-06-16T23:31:22.445Z",
    "dateUpdated": "2026-10-30T22:01:54.750Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-55614",
      "date": "2026-11-05",
      "epss": "0.00395",
      "percentile": "0.33898"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "uhttpd",
                "vendor": "openwrt",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, \u003c ae015e099986ceace44975cb69629841a2d58d37"
                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 2bef561c890f275ce3b785e6abdb3eda28c96aa8, \u003c 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "uhttpd is a small HTTP server. In unpatched repository snapshots, `client_parse_header()` in `client.c` lowercases header names but compares the `Transfer-Encoding` value to `chunked` using case-sensitive `strcmp`. A mixed-case transfer-coding token is accepted without enabling `r-\u003etransfer_chunked`, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the `chunked` POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue."
          }
        ],
        "id": "CVE-2026-55614",
        "lastModified": "2026-11-02T19:35:33.347",
        "metrics": {
          "cvssMetricV40": [
            {
              "cvssData": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "NONE",
                "attackVector": "NETWORK",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 6.9,
                "baseSeverity": "MEDIUM",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "NONE",
                "vulnConfidentialityImpact": "NONE",
                "vulnIntegrityImpact": "LOW",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-30T22:16:55.250",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/openwrt/uhttpd/commit/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/openwrt/uhttpd/commit/ae015e099986ceace44975cb69629841a2d58d37"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/openwrt/uhttpd/security/advisories/GHSA-mcfg-c4r7-pjpf"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
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            "description": [
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                "lang": "en",
                "value": "CWE-444"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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