Vulnerability · Published Sep 1, 2026 · Assigned by EEF

CVE-2026-74994inets, httpd: Authentication Bypass via Directory Namespace Collapse in httpd mod_auth

Medium 6.0

In plain English

A medium-severity incorrect authorization in OTP from Erlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.0Medium
Exploit odds (30 days)0.6%top 49.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

The mod_auth module in OTP's inets httpd server, when configured with dets or mnesia authentication backends and multiple directory configuration blocks, collapses all directory blocks into a single shared user/group namespace. A user added to one protected directory is accepted as valid for all other protected directories on the same server instance. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12erlangno fix listedDEBIAN-CVE-2026-74994
Debian:13erlang1:27.3.4.1+dfsg-1+deb13u4DEBIAN-CVE-2026-74994
Debian:14erlang1:29.0.6+dfsg-1DEBIAN-CVE-2026-74994
Ubuntu:22.04:LTSerlang1:24.2.1+dfsg-1ubuntu0.8UBUNTU-CVE-2026-74994
Ubuntu:22.04:LTSerlang1:24.2.1+dfsg-1ubuntu0.8USN-8901-1
Ubuntu:24.04:LTSerlang1:25.3.2.8+dfsg-1ubuntu4.8USN-8901-1
Ubuntu:24.04:LTSerlang1:25.3.2.8+dfsg-1ubuntu4.8UBUNTU-CVE-2026-74994
Ubuntu:26.04:LTSerlang1:27.3.4.6+dfsg-1ubuntu0.2USN-8901-1
Ubuntu:26.04:LTSerlang1:27.3.4.6+dfsg-1ubuntu0.2UBUNTU-CVE-2026-74994

Affected products (as reported)

VendorProductVersions
Erlang OTP 17.0 – before 27.3.4.1728.0 – before 28.5.0.629.0 – before 29.0.6
Erlang OTP 5.10 – before 9.3.2.79.4 – before 9.6.2.39.7 – before 9.7.2
Erlang OTP 84adefa331c4159d432d22840663c38f155cd4c1 – before *

Weakness: CWE-863, CWE-1289 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References