CVE-2026-74994 PUBLISHED

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

Assigner: EEF
Reserved: 17.08.2026 Published: 01.09.2026 Updated: 01.09.2026

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.

Metrics

CVSS 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
CVSS Score: 6

Product Status

Vendor Erlang
Product OTP
Versions Default: unaffected
  • unknown from 0 to 17.0 (excl.)
  • affected from 17.0 to 27.3.4.17 (excl.)
  • affected from 28.0 to 28.5.0.6 (excl.)
  • affected from 29.0 to 29.0.6 (excl.)
Vendor Erlang
Product OTP
Versions Default: unaffected
  • unknown from 0 to 5.10 (excl.)
  • affected from 5.10 to 9.3.2.7 (excl.)
  • affected from 9.4 to 9.6.2.3 (excl.)
  • affected from 9.7 to 9.7.2 (excl.)
Vendor Erlang
Product OTP
Versions Default: unaffected
  • affected from 84adefa331c4159d432d22840663c38f155cd4c1 to * (excl.)

Credits

  • Lukas Backström / Erlang Solutions finder
  • Konrad Pietrzak remediation developer

References

Problem Types

  • CWE-863 Incorrect Authorization CWE
  • CWE-1289 Improper Validation of Unsafe Equivalence in Input CWE

Impacts

  • CAPEC-122 Privilege Abuse
  • CAPEC-114 Authentication Abuse