CVE-2026-28808: high-severity vulnerability in Erlang OTP
ScriptAlias CGI targets bypass directory auth in inets httpd (mod_auth vs mod_cgi path mismatch)
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.3epss 0.6%
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/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
Erlang · OTPRelated CVEs — Erlang OTP
In the same product, most dangerous first.
CVE-2026-66835HIGHhttpd mod_auth directory protection bypassed by a doubled slash in the request pathEPSS 1.0%CVE-2026-69664HIGHhttpd parks a request worker indefinitely on a malformed chunk size sent after the headersEPSS 0.9%CVE-2026-73270HIGHhttpd mod_auth directory protection bypassed by request path casing on case-insensitive filesystemsEPSS 0.9%CVE-2026-70399HIGHhttpd does not enforce the documented default max_clients connection limitEPSS 0.9%CVE-2026-75538HIGHA Signed Length Overflow in Erlang/OTP's inet TCP Driver Overflows the Receive Buffer Into BEAM VM Memory From an Unauthenticated PeerEPSS 0.9%CVE-2026-59250HIGHMegaco flex scanner buffer overflow via oversized property parm nameEPSS 0.8%
References
https://access.redhat.com/security/cve/CVE-2026-28808https://bugzilla.redhat.com/show_bug.cgi?id=2455909https://cna.erlef.org/cves/CVE-2026-28808.htmlhttps://github.com/erlang/otp/commit/07b8f441ca711f9812fad9e9115bab3c3aa92f79https://github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82942688https://github.com/erlang/otp/commit/9dfa0c51eac97866078e808dec2183cb7871ff7chttps://github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3fhttps://osv.dev/vulnerability/EEF-CVE-2026-28808https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28808.jsonhttps://www.erlang.org/doc/system/versions.html#order-of-versions