CVE-2026-28808

Name	CVE-2026-28808
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
erlang (PTS)	bullseye	1:23.2.6+dfsg-1+deb11u1	vulnerable
	bullseye (security)	1:23.2.6+dfsg-1+deb11u3	vulnerable
	bookworm	1:25.2.3+dfsg-1+deb12u3	vulnerable
	bookworm (security)	1:25.2.3+dfsg-1+deb12u1	vulnerable
	trixie	1:27.3.4.1+dfsg-1+deb13u1	vulnerable
	forky	1:27.3.4.9+dfsg-1	vulnerable
	sid	1:27.3.4.10+dfsg-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
erlang	source	(unstable)	1:27.3.4.10+dfsg-1

Notes

https://github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3f
Fixed by: https://github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82942688 (OTP-27.3.4.10, OTP-28.4.2)
https://cna.erlef.org/cves/CVE-2026-28808.html