Description
Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias.
When script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory-based access controls against the DocumentRoot-relative path while mod_cgi executes the script at the ScriptAlias-resolved path. This path mismatch allows unauthenticated access to CGI scripts that directory rules were meant to protect.
This vulnerability is associated with program files lib/inets/src/http_server/mod_alias.erl, lib/inets/src/http_server/mod_auth.erl, and lib/inets/src/http_server/mod_cgi.erl.
This issue affects OTP from OTP 17.0 before OTP 26.2.5.19, OTP 27.3.4.10, and OTP 28.4.2, corresponding to inets from 5.10 before 9.1.0.6, 9.3.2.4, and 9.6.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Erlang | OTP | 17.0, 5.10 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | erlang | 1:27.3.4.10+dfsg-1 | — |
| Debian 13 | erlang | 1:27.3.4.1+dfsg-1+deb13u3 | — |
| Debian 12 | erlang | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | erlang | 1:27.3.4.6+dfsg-1ubuntu0.2 | USN-8901-1 |
| Ubuntu 25.10 | erlang | No fix yet | — |
| Ubuntu 24.04 LTS | erlang | 1:25.3.2.8+dfsg-1ubuntu4.8 | USN-8901-1 |
| Ubuntu 22.04 LTS | erlang | 1:24.2.1+dfsg-1ubuntu0.8 | USN-8901-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | erlang | 1:22.2.7+dfsg-1ubuntu0.5+esm3 | USN-8901-1 |
| Ubuntu Pro 18.04 LTS | erlang | 1:20.2.2+dfsg-1ubuntu2+esm4 | USN-8901-1 |
| Ubuntu Pro 16.04 LTS | erlang | 1:18.3-dfsg-1ubuntu3.1+esm4 | USN-8901-1 |
| Ubuntu Pro 14.04 LTS | erlang | 1:16.b.3-dfsg-1ubuntu2.2+esm3 | USN-8901-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | erlang | 28.5.0.4-1.1 | openSUSE-SU-2026:11559-1 |
| openSUSE Tumbleweed | erlang27 | 27.1.3-2.1 | openSUSE-SU-2026:10947-1 |
| openSUSE Leap 16.0 | erlang | 27.1.3-160000.4.1 | openSUSE-SU-2026:20607-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | erlang | 26.2.5.19-1 | — |
Advisories 5
- USN-8901-1 erlang vulnerabilities Ubuntu Security Notices (USN) · Oct 8, 2026
- WID-SEC-2026-0998 Erlang/OTP: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 24, 2026
- openSUSE-SU-2026:11559-1 erlang-28.5.0.4-1.1 on GA media SUSE / openSUSE Security Updates · Aug 21, 2026
- openSUSE-SU-2026:10947-1 erlang27-27.1.3-2.1 on GA media SUSE / openSUSE Security Updates · Jun 4, 2026
- openSUSE-SU-2026:20607-1 Security update for erlang SUSE / openSUSE Security Updates · Apr 24, 2026
References
- GitHub Advisory related vendor-advisory
- EEF CNA record for CVE-2026-28808 related
- OSV record EEF-CVE-2026-28808 related
- Erlang/OTP version ordering
- Introducing commit 07b8f44 in erlang/otp related
- Fix commit 8fc71ac in erlang/otp patch
- Fix commit 9dfa0c5 in erlang/otp patch