Erlang/OTP 29.1.1

OTP-20287

Application(s):

ssh

Related Id(s):

GH-SA-qhcm-px9c-rvfh, PR-11523, CVE-2026-68956

Fixed a vulnerability where the max_channels daemon option was not enforced for session channels without an active subsystem, allowing a remote authenticated user to open an infinite number of channels and exhaust server resources despite the configured limit.

The default value of the max_channels daemon option has been changed from infinity to 256. Deployments requiring more than 256 simultaneous channels per connection can restore the previous behavior by setting {max_channels, infinity}.

The default value of the max_sessions daemon option has been changed from infinity to 1024. Deployments requiring more concurrent SSH connections can restore the previous behavior by setting {max_sessions, infinity}.

The asn1-5.5.2 application can be applied independently of other applications on a full OTP 29 installation.

OTP-20272

Related Id(s):

PR-11655, CVE-2026-65634

Fixed a denial-of-service attack in asn1, where abnormally large OID components (arcs) could cause resource exhaustion.

OTP-20355

Related Id(s):

ERIERL-1355, PR-11559

The JER backend will no longer break certain values (true, false, null) when they are typed as ENUMERATED, they will now be encoded as strings as required by the standard.

Full runtime dependencies of asn1-5.5.2

erts-14.0, kernel-9.0, stdlib-5.0

The compiler-10.0.6 application can be applied independently of other applications on a full OTP 29 installation.

OTP-20386

Related Id(s):

GH-11619, PR-11638

Certain uses of funs could crash the compiler. For example:

f() ->
    F = fun Fn(0) -> 0; Fn(N) -> Fn(N - 1) end,
    [F(X) || X <- [1, 2]].

This has been corrected.

Full runtime dependencies of compiler-10.0.6

crypto-5.1, erts-13.0, kernel-8.4, stdlib-8.0

The public_key-1.21.7 application can be applied independently of other applications on a full OTP 29 installation.

OTP-20393

Related Id(s):

PR-11630

Handle that policy qualifiers are optional.

Full runtime dependencies of public_key-1.21.7

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

The ssh-6.0.6 application can be applied independently of other applications on a full OTP 29 installation.

OTP-20287

POTENTIAL INCOMPATIBILITY

 

Fixed a vulnerability where the max_channels daemon option was not enforced for session channels without an active subsystem, allowing a remote authenticated user to open an infinite number of channels and exhaust server resources despite the configured limit.

The default value of the max_channels daemon option has been changed from infinity to 256. Deployments requiring more than 256 simultaneous channels per connection can restore the previous behavior by setting {max_channels, infinity}.

The default value of the max_sessions daemon option has been changed from infinity to 1024. Deployments requiring more concurrent SSH connections can restore the previous behavior by setting {max_sessions, infinity}.

OTP-20371

Related Id(s):

ERIERL-1363, GH-11586, PR-11616

The SSH daemon no longer rejects a subsystem request that is preceded by env or pty-req request on the same channel.

Full runtime dependencies of ssh-6.0.6

crypto-5.7, erts-14.0, kernel-10.3, public_key-1.6.1, runtime_tools-1.15.1, stdlib-8.0

Note! The ssl-11.7.7 application cannot be applied independently of other applications on an arbitrary OTP 29 installation.

   On a full OTP 29 installation, also the following runtime
   dependency has to be satisfied:
   -- public_key-1.21.1 (first satisfied in OTP 29.0.1)

OTP-20388

Related Id(s):

PR-11641, CVE-2026-89422

Reject unsolicited TLS-1.3 pre_shared_key in client.

OTP-20390

Related Id(s):

PR-11651

Security and robustness hardening returning RFC mandated alert reasons, narrowing/correcting length checks.

Correct signature algorithm handling that slightly mixed up signature algorithms and signature algorithms cert in TLS-1.2.

Add missing TLS-1.3 Brainpool groups support. (Not relevant in 27 patch)

Enhanced/corrected documentation and spec errors/deviations.

Full runtime dependencies of ssl-11.7.7

crypto-5.8, erts-16.0, inets-5.10.7, kernel-10.3, public_key-1.21.1, runtime_tools-1.15.1, stdlib-7.0

Alan Duffield