CVE-2026-28808
Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.3 HIGHCVSS: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/M
- EPSS
- 0.56% probability · 45th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-863, CWE-551
- Affected
- erlang/erlang\/inets · erlang/erlang\/otp
- Source
- 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
References
- https://cna.erlef.org/cves/CVE-2026-28808.htmlMitigation, Vendor Advisory
- https://github.com/erlang/otp/commit/07b8f441ca711f9812fad9e9115bab3c3aa92f79
- 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-2026-28808Patch, Third Party Advisory
- https://www.erlang.org/doc/system/versions.html#order-of-versionsProduct
- https://access.redhat.com/security/cve/CVE-2026-28808
- https://bugzilla.redhat.com/show_bug.cgi?id=2455909
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28808.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.