Improper Handling of Case Sensitivity in Erlang OTP - CVE-2026-73270

Vulnerability identifier: #VU146836

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-73270

CWE-ID: CWE-178

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass authentication and access protected resources.

The vulnerability exists due to improper handling of case sensitivity in the mod_auth module in OTP's inets httpd server when processing requests for protected directory paths on case-insensitive filesystems. A remote attacker can request the same protected resource using different path casing to bypass authentication and access protected resources.

Only deployments on case-insensitive filesystems such as Windows and macOS are vulnerable, and exploitation requires one or more directory blocks configured with mod_auth.

Erlang OTP
PowerVC
Ubuntu
openEuler
Fedora
erlang-runtime_tools
erlang-compiler
erlang-common_test
erlang-asn1
erlang
erlang-xmerl
erlang-wx
erlang-tools
erlang-tftp
erlang-syntax_tools
erlang-stdlib
erlang-ssl
erlang-ssh
erlang-src
erlang-snmp
erlang-sasl
erlang-crypto
erlang-reltool
erlang-public_key
erlang-parsetools
erlang-os_mon
erlang-odbc
erlang-observer
erlang-mnesia
erlang-megaco
erlang-kernel
erlang-jinterface
erlang-inets
erlang-ftp
erlang-examples
erlang-eunit
erlang-et
erlang-erts
erlang-erl_interface
erlang-erl_docgen
erlang-eldap
erlang-edoc
erlang-diameter
erlang-dialyzer
erlang-debugsource
erlang-debuginfo
erlang-debugger
erlang (Ubuntu package)

Install security update from vendor's website.

Erlang OTP - addressed in versions 27.3.4.17, 28.5.0.6, 29.0.6
erlang-runtime_tools - update to 25.3.2.6-20
erlang-compiler - update to 25.3.2.6-20
erlang-common_test - update to 25.3.2.6-20
erlang-asn1 - update to 25.3.2.6-20
erlang - update to 25.3.2.6-20
erlang-xmerl - update to 25.3.2.6-20
erlang-wx - update to 25.3.2.6-20
erlang-tools - update to 25.3.2.6-20
erlang-tftp - update to 25.3.2.6-20
erlang-syntax_tools - update to 25.3.2.6-20
erlang-stdlib - update to 25.3.2.6-20
erlang-ssl - update to 25.3.2.6-20
erlang-ssh - update to 25.3.2.6-20
erlang-src - update to 25.3.2.6-20
erlang-snmp - update to 25.3.2.6-20
erlang-sasl - update to 25.3.2.6-20
erlang-crypto - update to 25.3.2.6-20
erlang-reltool - update to 25.3.2.6-20
erlang-public_key - update to 25.3.2.6-20
erlang-parsetools - update to 25.3.2.6-20
erlang-os_mon - update to 25.3.2.6-20
erlang-odbc - update to 25.3.2.6-20
erlang-observer - update to 25.3.2.6-20
erlang-mnesia - update to 25.3.2.6-20
erlang-megaco - update to 25.3.2.6-20
erlang-kernel - update to 25.3.2.6-20
erlang-jinterface - update to 25.3.2.6-20
erlang-inets - update to 25.3.2.6-20
erlang-ftp - update to 25.3.2.6-20
erlang-examples - update to 25.3.2.6-20
erlang-eunit - update to 25.3.2.6-20
erlang-et - update to 25.3.2.6-20
erlang-erts - update to 25.3.2.6-20
erlang-erl_interface - update to 25.3.2.6-20
erlang-erl_docgen - update to 25.3.2.6-20
erlang-eldap - update to 25.3.2.6-20
erlang-edoc - update to 25.3.2.6-20
erlang-diameter - update to 25.3.2.6-20
erlang-dialyzer - update to 25.3.2.6-20
erlang-debugsource - update to 25.3.2.6-20
erlang-debuginfo - update to 25.3.2.6-20
erlang-debugger - update to 25.3.2.6-20
erlang - addressed in versions 26.2.5.21-10.fc43, 26.2.5.21-10.fc44
erlang (Ubuntu package) - addressed in versions 1:16.b.3-dfsg-1ubuntu2.2+esm2, 1:18.3-dfsg-1ubuntu3.1+esm3, 1:20.2.2+dfsg-1ubuntu2+esm3, 1:22.2.7+dfsg-1ubuntu0.5+esm2, 1:24.2.1+dfsg-1ubuntu0.7, 1:25.3.2.8+dfsg-1ubuntu4.7, 1:27.3.4.6+dfsg-1ubuntu0.1

• https://github.com/erlang/otp/security/advisories/GHSA-mh78-93cr-jx8f

• Multiple vulnerabilities in Erlang OTP
• Ubuntu update for erlang
• openEuler 24.03 LTS SP4 update for erlang
• openEuler 24.03 LTS SP3 update for erlang
• openEuler 24.03 LTS SP1 update for erlang
• Multiple vulnerabilities in IBM PowerVC
• Fedora 44 update for erlang
• Fedora 43 update for erlang