Patch Package OTP 29.1.1 Released

Erlang News & Announcements Erlang News
1 
Patch Package:           OTP 29.1.1
Git Tag:                 OTP-29.1.1
Date:                    2026-09-22
Trouble Report Id:       OTP-20272, OTP-20287, OTP-20355, OTP-20371,
                         OTP-20386, OTP-20388, OTP-20390, OTP-20393
Seq num:                 CVE-2026-65634, CVE-2026-68956,
                         CVE-2026-89422, ERIERL-1355, ERIERL-1363,
                         GH-11586, GH-11619, GH-SA-qhcm-px9c-rvfh,
                         PR-11523, PR-11559, PR-11616, PR-11630,
                         PR-11638, PR-11641, PR-11651, PR-11655
System:                  OTP
Release:                 29
Application:             asn1-5.5.2, compiler-10.0.6,
                         public_key-1.21.7, ssh-6.0.6, ssl-11.7.7
Predecessor:             OTP 29.1

Check out the git tag OTP-29.1.1, 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

  • 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}.

    Own Id: OTP-20287
    Application(s): ssh
    Related Id(s): GH-SA-qhcm-px9c-rvfh, PR-11523, CVE-2026-68956

asn1-5.5.2

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

Fixed Bugs and Malfunctions

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

    Own Id: OTP-20272
    Related Id(s): PR-11655, CVE-2026-65634

  • 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.

    Own Id: OTP-20355
    Related Id(s): ERIERL-1355, PR-11559

Full runtime dependencies of asn1-5.5.2

erts-14.0, kernel-9.0, stdlib-5.0

compiler-10.0.6

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

Fixed Bugs and Malfunctions

  • 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.

    Own Id: OTP-20386
    Related Id(s): GH-11619, PR-11638

Full runtime dependencies of compiler-10.0.6

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

public_key-1.21.7

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

Fixed Bugs and Malfunctions

  • Handle that policy qualifiers are optional.

    Own Id: OTP-20393
    Related Id(s): PR-11630

Full runtime dependencies of public_key-1.21.7

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

ssh-6.0.6

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

Fixed Bugs and Malfunctions

  • 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}.

    Own Id: OTP-20287
    Related Id(s): GH-SA-qhcm-px9c-rvfh, PR-11523, CVE-2026-68956

    *** POTENTIAL INCOMPATIBILITY ***

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

    Own Id: OTP-20371
    Related Id(s): ERIERL-1363, GH-11586, PR-11616

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

ssl-11.7.7

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)

Fixed Bugs and Malfunctions

  • Reject unsolicited TLS-1.3 pre_shared_key in client.

    Own Id: OTP-20388
    Related Id(s): PR-11641, CVE-2026-89422

  • 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.

    Own Id: OTP-20390
    Related Id(s): PR-11651

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

Thanks to

Alan Duffield