---
id: CVE-2026-100698
title: >-
  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
summary: >-
  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 …
severity: medium
cvss: 5.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N'
cwe:
  - CWE-918
vendor: vrana
product: adminer
affected:
  - adminer < 6.0.2
published: '2026-09-26'
updated: '2026-09-26'
sourceUpdated: '2026-09-26T14:16:54.730'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100698'
references:
  - url: 'https://github.com/vrana/adminer/security/advisories/GHSA-rwxg-xph9-82cj'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/adminer-before-6.0.2-privileged-port-ssrf-via-host-port-regex
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-26T13:33:20.902Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.