CVE-2026-28808 | Mondoo Vulnerability Intelligence

CVE-2026-28808

CRITICAL9.8

ScriptAlias CGI targets bypass directory auth in inets httpd (mod_auth vs mod_cgi path mismatch)

Published Apr 7, 2026

Modified 1 months ago

Details

Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias.

When script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory-based access controls against the DocumentRoot-relative path while mod_cgi executes the script at the ScriptAlias-resolved path. This path mismatch allows unauthenticated access to CGI scripts that directory rules were meant to protect.

This vulnerability is associated with program files lib/inets/src/http_server/mod_alias.erl, lib/inets/src/http_server/mod_auth.erl, and lib/inets/src/http_server/mod_cgi.erl.

This issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to inets from 5.10 until 9.6.2, 9.3.2.4 and 9.1.0.6.

References

WEB

https://cna.erlef.org/cves/CVE-2026-28808.html

FIX

https://github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82942688

FIX

https://github.com/erlang/otp/commit/9dfa0c51eac97866078e808dec2183cb7871ff7c

ADVISORY

https://github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3f

WEB

https://osv.dev/vulnerability/EEF-CVE-2026-28808