CVE-2026-28808

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

Published: Apr 7, 2026Updated: Sep 8, 2026 Sources: CVE List NVDCWE-863

9.8CRITICAL

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 before OTP 26.2.5.19, OTP 27.3.4.10, and OTP 28.4.2, corresponding to inets from 5.10 before 9.1.0.6, 9.3.2.4, and 9.6.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:HConfidentiality

High

I:HIntegrity

High

A:HAvailability

High

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Weaknesses

CWE-863 CWE-551

Affected Products

Erlang

oss-projectaka erlang/otp, otp, erlang/ssh

OTPLibraryLibrary

OSS Libraries / generic-library

erlang\/inetsLibraryLibrary

OSS Libraries / generic-library

erlang\/otpLibraryLibrary

OSS Libraries / generic-library

Exploitability

Official Patch Available

Workaround Available

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Initial Access

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References

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

github.com

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

cna.erlef.org

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

osv.dev

and 7 more references View all →

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