UBUNTU-CVE-2026-100698 (CVE-2026-100698)

Vulnerability from osv_ubuntu – Published: 2026-09-26 14:16 – Updated: 2026-09-30 21:41 – Source website
VLAI
Details

Adminer 5.5.1 through 6.0.1 improperly parses the login 'server' string in the host_port() function in adminer/include/functions.inc.php. The port capture group requires pure digits anchored to the end of the string, so any server value with a non-digit tail fails the regex and falls back to returning the whole string as the host with an empty port. Because the privileged-port restriction in adminer/include/auth.inc.php inspects only the parsed port, the check is skipped, and the mysqli/mysqlnd client subsequently re-parses host:port from the host string and opens a TCP connection. A remote, unauthenticated attacker who can reach the Adminer login page can submit a crafted value such as 127.0.0.1:80/x to make the server initiate TCP connections to arbitrary internal hosts and privileged ports before credentials are validated, enabling server-side request forgery and blind internal port scanning (connection refused vs. handshake vs. timeout acts as a liveness oracle). This is a regression that re-opens the bypass fixed in 5.5.0 (GHSA-58cq-mgw2-38m5). Fixed in 6.0.2.

Severity
5.8 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
6.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "adminer",
            "binary_version": "4.2.1-1ubuntu1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "adminer",
        "purl": "pkg:deb/ubuntu/adminer@4.2.1-1ubuntu1+esm1?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.2.1-1",
        "4.2.1-1ubuntu1",
        "4.2.1-1ubuntu1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "adminer",
            "binary_version": "4.6.2-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "adminer",
        "purl": "pkg:deb/ubuntu/adminer@4.6.2-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.3.1-2",
        "4.5.0-1",
        "4.6.1-1",
        "4.6.2-1",
        "4.6.2-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "adminer",
            "binary_version": "4.7.6-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "adminer",
        "purl": "pkg:deb/ubuntu/adminer@4.7.6-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.7.2-1",
        "4.7.4-1",
        "4.7.5-1",
        "4.7.6-1",
        "4.7.6-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "adminer",
            "binary_version": "4.8.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "adminer",
        "purl": "pkg:deb/ubuntu/adminer@4.8.1-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.7.9-2",
        "4.8.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "adminer",
            "binary_version": "4.8.1-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "adminer",
        "purl": "pkg:deb/ubuntu/adminer@4.8.1-2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.8.1-1",
        "4.8.1-1ubuntu1",
        "4.8.1-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "adminer",
            "binary_version": "5.4.1+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "adminer",
        "purl": "pkg:deb/ubuntu/adminer@5.4.1+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.2.1+dfsg-1",
        "5.3.0+dfsg-1",
        "5.4.0+dfsg-1",
        "5.4.1+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "Adminer 5.5.1 through 6.0.1 improperly parses the login \u0027server\u0027 string in the host_port() function in adminer/include/functions.inc.php. The port capture group requires pure digits anchored to the end of the string, so any server value with a non-digit tail fails the regex and falls back to returning the whole string as the host with an empty port. Because the privileged-port restriction in adminer/include/auth.inc.php inspects only the parsed port, the check is skipped, and the mysqli/mysqlnd client subsequently re-parses host:port from the host string and opens a TCP connection. A remote, unauthenticated attacker who can reach the Adminer login page can submit a crafted value such as 127.0.0.1:80/x to make the server initiate TCP connections to arbitrary internal hosts and privileged ports before credentials are validated, enabling server-side request forgery and blind internal port scanning (connection refused vs. handshake vs. timeout acts as a liveness oracle). This is a regression that re-opens the bypass fixed in 5.5.0 (GHSA-58cq-mgw2-38m5). Fixed in 6.0.2.",
  "id": "UBUNTU-CVE-2026-100698",
  "modified": "2026-09-30T21:41:52Z",
  "published": "2026-09-26T14:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-100698"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-100698"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/vrana/adminer/security/advisories/GHSA-rwxg-xph9-82cj"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/adminer-before-6.0.2-privileged-port-ssrf-via-host-port-regex"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-100698"
  ]
}



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