CVE-2026-74994

inets, httpd: Authentication Bypass via Directory Namespace Collapse in httpd mod_auth

MEDIUM
6
CVSS Score
Published: September 1, 2026 at 02:45 PM UTC
Updated: September 8, 2026 at 02:17 AM UTC
1 product affected across 1 vendorErlang /otp

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Severity
MEDIUM6
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 27.3.4.1717.0 ≤ v < 27.3.4.1728.0 ≤ v < 28.5.0.629.0 ≤ v < 29.0.65.10 ≤ v < 9.3.2.79.4 ≤ v < 9.6.2.39.7 ≤ v < 9.7.217.028.029.05.1084adefa331c4159d432d22840663c38f155cd4c19.49.7
Affected range stops below 27.3.4.17, so it looks safe — our inference, not a vendor statement
Affected range stops below 28.5.0.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 29.0.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.3.2.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.6.2.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.7.2, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 17.0 (unknown)
Vendor states this is fixed in 5.10 (unknown)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6MEDIUMEEF
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-863CWE-1289

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