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.
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
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | erlang | no fix listed | DEBIAN-CVE-2026-74994 |
| Debian:13 | erlang | 1:27.3.4.1+dfsg-1+deb13u4 | DEBIAN-CVE-2026-74994 |
| Debian:14 | erlang | 1:29.0.6+dfsg-1 | DEBIAN-CVE-2026-74994 |
| Ubuntu:22.04:LTS | erlang | 1:24.2.1+dfsg-1ubuntu0.8 | UBUNTU-CVE-2026-74994 |
| Ubuntu:22.04:LTS | erlang | 1:24.2.1+dfsg-1ubuntu0.8 | USN-8901-1 |
| Ubuntu:24.04:LTS | erlang | 1:25.3.2.8+dfsg-1ubuntu4.8 | USN-8901-1 |
| Ubuntu:24.04:LTS | erlang | 1:25.3.2.8+dfsg-1ubuntu4.8 | UBUNTU-CVE-2026-74994 |
| Ubuntu:26.04:LTS | erlang | 1:27.3.4.6+dfsg-1ubuntu0.2 | USN-8901-1 |
| Ubuntu:26.04:LTS | erlang | 1:27.3.4.6+dfsg-1ubuntu0.2 | UBUNTU-CVE-2026-74994 |
Affected products (as reported)
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
- https://github.com/erlang/otp/security/advisories/GHSA-c3cq-q8x6-547g vendor-advisory
- https://cna.erlef.org/cves/CVE-2026-74994.html related
- https://osv.dev/vulnerability/EEF-CVE-2026-74994 related
- https://github.com/erlang/otp/commit/6982e381137ede21a4e1faf5fa2dd82321691176 patch
- https://github.com/erlang/otp/commit/c5ccec8ed25c70ec6557fd81277e4b2f52285c19 patch
- https://github.com/erlang/otp/commit/6101cb74ff2870718c622ba7af0c100f7f2524e3 patch