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UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-100698

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.

MEDIUM 6.9EPSS 0.35%

Does this matter?

Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 4.0
6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.35% probability · 28th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-918
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%27 September 2026: 0.28%26 October 2026: 0.35%27 September 202626 October 2026

EPSS moved from 0.3% on 27 September 2026 to 0.3% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.