FKIE_CVE-2026-55612

Vulnerability from fkie_nvd - Published: 2026-10-30 22:16 - Updated: 2026-11-02 19:35
Severity
3.7 (Low) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Summary
uhttpd is a small HTTP server. In unpatched repository snapshots, `client_poll_post_data()` in `client.c` consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears `r->content_length` and `r->transfer_chunked` without draining the remaining body or setting `request.connection_close`. The completion check treats the chunked POST as finished and the keep-alive parser returns to `CLIENT_STATE_INIT`. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue.
References
security-advisories@github.comhttps://github.com/openwrt/uhttpd/commit/34460b8211d676ef1b9f40d6b775c5e112933690
security-advisories@github.comhttps://github.com/openwrt/uhttpd/commit/b78f518478794e16ba3568fc1258e40bf3e8eb3b
security-advisories@github.comhttps://github.com/openwrt/uhttpd/security/advisories/GHSA-p55c-rmhc-qfm5
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "uhttpd",
          "vendor": "openwrt",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= b7c85a2819b3869279a669d5681f574824589c6c, \u003c b78f518478794e16ba3568fc1258e40bf3e8eb3b"
            },
            {
              "status": "affected",
              "version": "\u003e= b7c85a2819b3869279a669d5681f574824589c6c, \u003c 34460b8211d676ef1b9f40d6b775c5e112933690"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "uhttpd is a small HTTP server. In unpatched repository snapshots, `client_poll_post_data()` in `client.c` consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears `r-\u003econtent_length` and `r-\u003etransfer_chunked` without draining the remaining body or setting `request.connection_close`. The completion check treats the chunked POST as finished and the keep-alive parser returns to `CLIENT_STATE_INIT`. Attacker-controlled body bytes aligned as a complete HTTP request are then parsed and processed as another request on the same connection, causing HTTP request smuggling and request-boundary desynchronization. Commits b78f518478794e16ba3568fc1258e40bf3e8eb3b and 34460b8211d676ef1b9f40d6b775c5e112933690 patch the issue."
    }
  ],
  "id": "CVE-2026-55612",
  "lastModified": "2026-11-02T19:35:33.347",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-55612",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-11-02T17:03:23.416603Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-30T22:16:54.950",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openwrt/uhttpd/commit/34460b8211d676ef1b9f40d6b775c5e112933690"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openwrt/uhttpd/commit/b78f518478794e16ba3568fc1258e40bf3e8eb3b"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openwrt/uhttpd/security/advisories/GHSA-p55c-rmhc-qfm5"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-444"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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