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.
CVSS Base Scores
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
Affected Products
| Vendor | Product | Version | Status |
|---|---|---|---|
| Erlang | OTP | 5.10 | affected |
| Erlang | OTP | 17.0 | — |
| Erlang | OTP | 07b8f441ca711f9812fad9e9115bab3c3aa92f79 | — |
Credits
- Igor Morgenstern / Aisle Research(reporter)
- Konrad Pietrzak(remediation developer)
References
- https://github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3f
- https://cna.erlef.org/cves/CVE-2026-28808.html
- https://osv.dev/vulnerability/EEF-CVE-2026-28808
- https://www.erlang.org/doc/system/versions.html#order-of-versions
- https://github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82942688
- https://github.com/erlang/otp/commit/9dfa0c51eac97866078e808dec2183cb7871ff7c