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.
Affected products
erlang: erlang\/inets; erlang: erlang\/otp
References10
- cna.erlef.org/cves/CVE-2026-28808.html MitigationVendor Advisory
- github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82… Patch
- github.com/erlang/otp/commit/9dfa0c51eac97866078e808dec2183cb78… Patch
- osv.dev/vulnerability/EEF-CVE-2026-28808 PatchThird Party Advisory
- github.com/erlang/otp/commit/07b8f441ca711f9812fad9e9115bab3c3a…
- github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3f Third Party Advisory
- www.erlang.org/doc/system/versions.html#order-of-versions Product
- access.redhat.com/security/cve/CVE-2026-28808
- bugzilla.redhat.com/show_bug.cgi?id=2455909
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28808…
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
8.3
HIGH
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 47 · as of 12 November 2026
- CWE
- CWE-863CWE-551
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