CVE-2026-55612

Full vulnerability record from the local CVENow database.

Description

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.

Severity

LOW

CVSS score

3.7 (v3.1)

Vulnerability status

Received

Source identifier

[email protected]

Published

2026-10-30 22:16:54.950000

Last modified

2026-10-30 22:16:54.950000

View original CVE JSON

{
  "id": "CVE-2026-55612",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-30T22:16:54.950",
  "lastModified": "2026-10-30T22:16:54.950",
  "vulnStatus": "Received",
  "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->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."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "openwrt",
          "product": "uhttpd",
          "versions": [
            {
              "version": ">= b7c85a2819b3869279a669d5681f574824589c6c, < b78f518478794e16ba3568fc1258e40bf3e8eb3b",
              "status": "affected"
            },
            {
              "version": ">= b7c85a2819b3869279a669d5681f574824589c6c, < 34460b8211d676ef1b9f40d6b775c5e112933690",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-444"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/openwrt/uhttpd/commit/34460b8211d676ef1b9f40d6b775c5e112933690",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/openwrt/uhttpd/commit/b78f518478794e16ba3568fc1258e40bf3e8eb3b",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/openwrt/uhttpd/security/advisories/GHSA-p55c-rmhc-qfm5",
      "source": "[email protected]"
    }
  ]
}