Patch Package:           OTP 28.5.0.1
Git Tag:                 OTP-28.5.0.1
Date:                    2026-05-27
Trouble Report Id:       OTP-20112, OTP-20116, OTP-20119, OTP-20123,
                         OTP-20126, OTP-20128, OTP-20129, OTP-20130,
                         OTP-20131, OTP-20134, OTP-20138, OTP-20140,
                         OTP-20141
Seq num:                 CVE-2026-42789, CVE-2026-42790, ERIERL-1314,
                         ERIERL-1315, ERIERL-1321, GH-10968, GH-11030,
                         GH-11088, OTP-20102, PR-11007, PR-11032,
                         PR-11062, PR-11067, PR-11079, PR-11089,
                         PR-11100, PR-11123, PR-11124, PR-11125,
                         PR-11136
System:                  OTP
Release:                 28
Application:             compiler-9.0.6.1, erts-16.4.0.1,
                         inets-9.6.2.1, kernel-10.6.3.1,
                         public_key-1.20.3.1, snmp-5.20.2.1,
                         ssl-11.6.0.1, wx-2.5.4.1
Predecessor:             OTP 28.5

Check out the git tag OTP-28.5.0.1, and build a full OTP system including documentation. Apply one or more applications from this build as patches to your installation using the 'otp_patch_apply' tool. For information on install requirements, see descriptions for each application version below.

POTENTIAL INCOMPATIBILITIES

• 'public_key', Adhere to RFC 9525, and remove support for legacy fallback to check hostname against subject common name. Also improve error handling creating two separate errors for name constraint check for subject names and subject alternative names.

  'ssl'. Error handling is slightly changed to better reflect public_key behaviour.

  Own Id: OTP-20130
  Application(s): public_key, ssl
  Related Id(s): PR-11124, CVE-2026-42790

compiler-9.0.6.1

The compiler-9.0.6.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• In rare circumstances, optimization of boolean expressions could invert the boolean value.

  Own Id: OTP-20140
  Related Id(s): GH-11088, PR-11089

Full runtime dependencies of compiler-9.0.6.1

crypto-5.1, erts-13.0, kernel-8.4, stdlib-6.0

erts-16.4.0.1

The erts-16.4.0.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• Fixed erlang:md5_init to always return the same deterministic context binary. Only an issue in OTP 28.5 when OTP was built with --disable-builtin-openssl or --enable-use-embedded-3pp-alternatives.

  Own Id: OTP-20123

• Added explicit configure test for C++ function std::to_chars if options --disable-builtin-ryu or --enable-use-embedded-3pp-alternatives is used.

  Own Id: OTP-20126
  Related Id(s): PR-11067

Full runtime dependencies of erts-16.4.0.1

kernel-9.0, sasl-3.3, stdlib-4.1

inets-9.6.2.1

The inets-9.6.2.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• A call to httpd:reload_config/2 now validates the new configuration before removing the old one, leaving the server running in case of faulty config, instead of putting it in an unrecoverable state.

  Own Id: OTP-20128
  Related Id(s): ERIERL-1314, PR-11079

Full runtime dependencies of inets-9.6.2.1

erts-14.0, kernel-9.0, mnesia-4.12, public_key-1.13, runtime_tools-1.8.14, ssl-9.0, stdlib-5.0, stdlib-6.0

kernel-10.6.3.1

The kernel-10.6.3.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• Incorrect TOS format when using gen_udp with socket backend

  Own Id: OTP-20131
  Related Id(s): GH-10968, OTP-20102

• SCTP peeloff of an IPv6 socket, the peeled-off socket does not inherit the parent options as expected.

  Own Id: OTP-20134
  Related Id(s): PR-11007

Full runtime dependencies of kernel-10.6.3.1

crypto-5.0, erts-15.2.5, sasl-3.0, stdlib-7.0

public_key-1.20.3.1

Note! The public_key-1.20.3.1 application cannot be applied independently of other applications on an arbitrary OTP 28 installation.

   On a full OTP 28 installation, also the following runtime
   dependency has to be satisfied:
   -- crypto-5.8 (first satisfied in OTP 28.3)

Fixed Bugs and Malfunctions

• OCSP responder certificates are now checked for expiration before being accepted as authorized responders. Previously, expired or not-yet-valid responder certificates were incorrectly accepted when verifying OCSP responses.

  Own Id: OTP-20112
  Related Id(s): PR-11136

• Corrected basic constraint path validation check in accordance to RFC 5280.

  Own Id: OTP-20129
  Related Id(s): PR-11123, CVE-2026-42789

• 'public_key', Adhere to RFC 9525, and remove support for legacy fallback to check hostname against subject common name. Also improve error handling creating two separate errors for name constraint check for subject names and subject alternative names.

  'ssl'. Error handling is slightly changed to better reflect public_key behaviour.

  Own Id: OTP-20130
  Related Id(s): PR-11124, CVE-2026-42790

  *** POTENTIAL INCOMPATIBILITY ***

Full runtime dependencies of public_key-1.20.3.1

asn1-5.0, crypto-5.8, erts-13.0, kernel-8.0, stdlib-4.0

snmp-5.20.2.1

The snmp-5.20.2.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• Fixed a bug in snmpm_usm:generate_outgoing_msg/5 that caused a badmatch crash when constructing an error response for an unknown user/engineID combination.

  Own Id: OTP-20138
  Related Id(s): ERIERL-1321, PR-11100

Full runtime dependencies of snmp-5.20.2.1

asn1-5.4, crypto-4.6, erts-12.0, kernel-8.0, mnesia-4.12, runtime_tools-1.8.14, stdlib-5.0

ssl-11.6.0.1

Note! The ssl-11.6.0.1 application cannot be applied independently of other applications on an arbitrary OTP 28 installation.

   On a full OTP 28 installation, also the following runtime
   dependencies have to be satisfied:
   -- crypto-5.8 (first satisfied in OTP 28.3)
   -- public_key-1.20.3.1 (first satisfied in OTP 28.5.0.1)

Fixed Bugs and Malfunctions

• Add missing clauses to ssl_handshake:extension_value/1. If an hello extension, missing a handling clause was present in a paused handshake, the handshake would fail.

  Own Id: OTP-20116
  Related Id(s): GH-11030, PR-11062

• 'public_key', Adhere to RFC 9525, and remove support for legacy fallback to check hostname against subject common name. Also improve error handling creating two separate errors for name constraint check for subject names and subject alternative names.

  'ssl'. Error handling is slightly changed to better reflect public_key behaviour.

  Own Id: OTP-20130
  Related Id(s): PR-11124, CVE-2026-42790

  *** POTENTIAL INCOMPATIBILITY ***

• Could cause server to terminate a connection without an alert towards a bad client.

  Own Id: OTP-20141
  Related Id(s): PR-11125

Full runtime dependencies of ssl-11.6.0.1

crypto-5.8, erts-16.0, inets-5.10.7, kernel-10.3, public_key-1.20.3.1, runtime_tools-1.15.1, stdlib-7.0

wx-2.5.4.1

The wx-2.5.4.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• The examples for wx are now only installed in one place (in doc/examples).

  Own Id: OTP-20119
  Related Id(s): ERIERL-1315, PR-11032

Full runtime dependencies of wx-2.5.4.1

erts-12.0, kernel-8.0, stdlib-5.0

Thanks to

Martin Hässler, Paul Guyot