Vulnerability 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 Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Erlang | Erlang\/Inets | >= 5.10, < 9.1.0.6 |
| Erlang | Erlang\/Otp | >= 17.0, < 26.2.5.19 |
Related Weaknesses (CWE)
References
- https://cna.erlef.org/cves/CVE-2026-28808.htmlVendor AdvisoryMitigation
- https://github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82942688Patch
- https://github.com/erlang/otp/commit/9dfa0c51eac97866078e808dec2183cb7871ff7cPatch
- https://github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3fThird Party Advisory
- https://osv.dev/vulnerability/EEF-CVE-2026-28808Third Party AdvisoryPatch
- https://www.erlang.org/doc/system/versions.html#order-of-versionsProduct
FAQ
What is CVE-2026-28808?
CVE-2026-28808 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 UR...
How severe is CVE-2026-28808?
CVE-2026-28808 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-28808?
Check the references section above for vendor advisories and patch information. Affected products include: Erlang Erlang\/Inets, Erlang Erlang\/Otp.