Patch Package:           OTP 28.5.0.6
Git Tag:                 OTP-28.5.0.6
Date:                    2026-09-01
Trouble Report Id:       OTP-20135, OTP-20234, OTP-20264, OTP-20265,
                         OTP-20268, OTP-20269, OTP-20270, OTP-20271,
                         OTP-20274, OTP-20278, OTP-20279, OTP-20281,
                         OTP-20282, OTP-20284, OTP-20286, OTP-20289,
                         OTP-20296, OTP-20300, OTP-20302, OTP-20306,
                         OTP-20307, OTP-20308, OTP-20312, OTP-20319,
                         OTP-20320, OTP-20324, OTP-20330, OTP-20333,
                         OTP-20334, OTP-20342, OTP-20343, OTP-20344,
                         OTP-20345, OTP-20346, OTP-20347, OTP-20350,
                         OTP-20351
Seq num:                 CVE-2026-75538, ERIERL-1354, GH-11052,
                         GH-11278, GH-11308, GH-11380, GH-11404,
                         GH-11416, GH-11419, GH-11423, GH-11494,
                         GH-11511, PR-11298, PR-11325, PR-11388,
                         PR-11417, PR-11425, PR-11428, PR-11429,
                         PR-11437, PR-11463, PR-11464, PR-11478,
                         PR-11481, PR-11485, PR-11492, PR-11503,
                         PR-11505, PR-11509, PR-11513, PR-11517,
                         PR-11521, PR-11533, PR-11538, PR-11539,
                         PR-11540, PR-11541, PR-11542, PR-11543,
                         PR-11544, PR-11545, PR-11546, PR-11547,
                         PR-11548, PR-11553, PR-11554
System:                  OTP
Release:                 28
Application:             compiler-9.0.6.2, crypto-5.8.3.3,
                         eldap-1.2.16.1, erl_interface-5.7.0.2,
                         erts-16.4.0.6, inets-9.6.2.3,
                         kernel-10.6.3.4, megaco-4.8.3.2,
                         mnesia-4.25.3.2, snmp-5.20.2.2, ssh-5.5.2.5,
                         ssl-11.6.0.5, stdlib-7.3.0.2, tools-4.1.4.1
Predecessor:             OTP 28.5.0.5

Check out the git tag OTP-28.5.0.6, 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.

compiler-9.0.6.2

The compiler-9.0.6.2 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• compiler: Fix bug in beam_types:subtract/2 for bitstrings

  Own Id: OTP-20312
  Related Id(s): GH-11494, PR-11503

Full runtime dependencies of compiler-9.0.6.2

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

crypto-5.8.3.3

The crypto-5.8.3.3 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• Fixed type mismatch between ErlNifUInt64 and uint64_t in crypto NIF that caused incompatible-pointer warnings on macOS arm64 when passing DH parameters to OpenSSL.

  Own Id: OTP-20333
  Related Id(s): GH-11511, PR-11513

Full runtime dependencies of crypto-5.8.3.3

erts-9.0, kernel-6.0, stdlib-3.9

eldap-1.2.16.1

The eldap-1.2.16.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• eldap referral URL parsing now rejects a port component longer than 5 digits instead of attempting to convert an arbitrarily large digit string to an integer.

  Own Id: OTP-20345
  Related Id(s): PR-11538

Full runtime dependencies of eldap-1.2.16.1

asn1-3.0, erts-6.0, kernel-3.0, ssl-5.3.4, stdlib-3.4

erl_interface-5.7.0.2

The erl_interface-5.7.0.2 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• erl_interface: Fix buffer leak and state corruption on ei_x_buff realloc failure

  Own Id: OTP-20324
  Related Id(s): PR-11492

erts-16.4.0.6

The erts-16.4.0.6 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• No-suspend port command signals (i.e. port command signals sent using the erlang:port_command/3 BIF or the erlang:send/3 BIF with the nosuspend option) were not aborted properly in all scenarios which could leave the port queue in a busy state indefinitely. Also asynchronously sent no-suspend command signals (i.e, port command signals sent using the erlang:send/3 BIF with the nosuspend option) could sometimes be delivered even though the port was busy.

  Own Id: OTP-20135
  Related Id(s): GH-11052, PR-11463

• erts: Fix missing exit_status caused by SIGCHLD race

  Own Id: OTP-20274
  Related Id(s): GH-11278, PR-11298

• erts: Fix bug in is_in_range instruction for x86 JIT

  Own Id: OTP-20278
  Related Id(s): GH-11419, PR-11429

• Fixed bug in binary_to_term that could cause emulator crash for specific terms in specific process states (reductions left).

  Own Id: OTP-20281
  Related Id(s): GH-11404, PR-11425

• erts: Fix crash with term_to_iovec/2 for large binary

  Own Id: OTP-20282
  Related Id(s): PR-11428

• A distributed priority send larger than 32 KiB to a process alias caused the receiving runtime system to crash.

  Own Id: OTP-20286
  Related Id(s): GH-11416, PR-11417

• Priority message queue markers were sometimes installed in the message queue even when no priority messages could be received. As a result, the two markers had to be traversed unnecessarily when scanning the message queue, introducing a small but avoidable overhead.

  Own Id: OTP-20300
  Related Id(s): PR-11485

• A monitor of time_offset co-created with a process alias (monitor(time_offset, clock_service, [{alias, UnaliasOpt}])) either crashed the runtime system or did not work. This bug was introduced in OTP 25.0.

  Own Id: OTP-20319
  Related Id(s): PR-11509

• A process alias was erroneously created when a remote spawn_request() operation with a {monitor, [{alias, explicit_unalias}]} option failed with noconnection reason.

  Own Id: OTP-20330
  Related Id(s): PR-11521

• A gen_tcp socket using the inet driver and {packet,4} had a bug if receiving a packet with size just below INT_MAX.

  That packet size wrapped in size calculations and made the received data overwrite its allocation and trash allocator metadata and subsequent block(s), causing the VM to crash.

  This made it possible for anyone to remotely crash an Erlang node that used {packet,4} on a reachable socket.

  This bug has been corrected.

  Own Id: OTP-20334
  Related Id(s): PR-11533, CVE-2026-75538

Full runtime dependencies of erts-16.4.0.6

kernel-9.0, sasl-3.3, stdlib-4.1

inets-9.6.2.3

The inets-9.6.2.3 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• The dets and mnesia mod_auth backends used a key that did not include the directory path, so all require_user/require_group records collapsed into one per-listener namespace. A user authorized for one protected directory could authenticate against any other protected directory served by the same listener. {path, Directory} is now included in the auth backend key, scoping records per directory as documented.

  Own Id: OTP-20264
  Related Id(s): PR-11546

• Requests specifying both Transfer-Encoding and Content-Length headers are now rejected with 400 Bad Request, per RFC 9112 Section 6.3. Previously such requests could be used for CL.TE request-smuggling/desync attacks against reverse proxies in front of httpd.

  Own Id: OTP-20268
  Related Id(s): PR-11547

• httpd accepted the obsolete header line-folding syntax (RFC 9112 Section 5.2, a continuation line beginning with space/tab), silently treating the folded continuation as a separate header. This allowed CL.TE-style request smuggling when httpd was placed behind a folding-aware proxy. Such requests are now rejected with 400 Bad Request.

  Own Id: OTP-20269
  Related Id(s): PR-11544

• A header such as Content-Length : 6 (whitespace before the colon) was previously silently dropped, causing the content length to default to 0 and the body bytes to be misinterpreted as a pipelined request (CL.0 smuggling). Per RFC 7230 Section 3.2.4, such headers are now rejected with 400 Bad Request.

  Own Id: OTP-20270
  Related Id(s): PR-11545

• A new httpd option request_timeout (default 60 seconds, renamed from the interim max_body_read_timeout) bounds the idle time between reads of a request body/message. The server now also sends 408 Request Timeout when the min_bytes_per_second floor is hit, and keep_alive_timeout measurement was corrected so the timer is cancelled as soon as new data arrives rather than only after full header parsing; keep_alive_timeout and request_timeout now also accept infinity to disable the timeout.

  Own Id: OTP-20271
  Related Id(s): PR-11543

• mod_auth, mod_security, and mod_get compared resolved filesystem paths against configured protected-directory patterns without normalizing repeated slashes or filesystem case. On case-insensitive filesystems (macOS, Windows) or with repeated slashes, a request could resolve to a protected resource while evading the directory match. Paths are now canonicalized (slash-collapsed, and case-normalized when the filesystem is case-insensitive) before the authorization decision.

  Own Id: OTP-20279
  Related Id(s): PR-11542

• A request with an invalid chunked transfer-encoding chunk size previously caused the httpd connection handler to hang indefinitely without requiring further input from the client. This leaked a process per request and could be used to exhaust server resources (denial of service). Invalid chunk sizes are now rejected immediately with an error response, and the connection is closed.

  Own Id: OTP-20306
  Related Id(s): PR-11539

• max_body_size was previously enforced only after a complete chunk had been received, allowing a single oversized chunk to be buffered in full before the limit was checked — undermining the memory-exhaustion protection the option is meant to provide. The limit is now enforced incrementally as chunk data arrives, rejecting the request as soon as the configured size is exceeded.

  Own Id: OTP-20307
  Related Id(s): PR-11540

• The documented default of 150 for the max_clients option was not applied by the implementation, allowing an unbounded number of concurrent clients to connect regardless of configuration. The default is now correctly enforced.

  Own Id: OTP-20308
  Related Id(s): PR-11541

• Fixed a bug where httpd failed to start when configured with {socket_type, {ip_comm, SockOpts}} and a fixed (non-zero) port.

  Own Id: OTP-20342
  Related Id(s): PR-11548

• httpc now enforces a limit on the total size of response headers and response body, preventing unbounded memory allocation when connecting to a malicious or malfunctioning server. The new max_header_size and max_body_size request options can be used to override the default limit (10240 bytes for headers). Additionally, httpc now validates that the Content-Length header contains only digits before use, avoiding a crash on malformed responses.

  Own Id: OTP-20343
  Related Id(s): PR-11538

Full runtime dependencies of inets-9.6.2.3

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-10.6.3.4

The kernel-10.6.3.4 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• A field in net_kernel's internal state was not cleaned up in some cases for failed connections could cause the state to grow indefinitely over time. This has now been fixed.

  Own Id: OTP-20265
  Related Id(s): GH-11308, PR-11388

Full runtime dependencies of kernel-10.6.3.4

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

megaco-4.8.3.2

The megaco-4.8.3.2 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• Numeric fields in megaco text-encoded messages are now validated for digit-string length before integer conversion, improving robustness of the text decoder. Per-field digit limits based on the H.248.1 ASN.1 type constraints are enforced (e.g., 10 digits for UINT32, 2 digits for timer values), along with a 100 KB overall message size cap at the scanner entry point. The binary (BER/PER) codec is not affected.

  Own Id: OTP-20234
  Related Id(s): PR-11325

Full runtime dependencies of megaco-4.8.3.2

asn1-3.0, debugger-4.0, erts-12.0, et-1.5, kernel-8.0, runtime_tools-1.8.14, stdlib-2.5

mnesia-4.25.3.2

The mnesia-4.25.3.2 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• A transaction iterating a table (first/1, last/1, next/2, prev/2, select, select_reverse on non-ordered_set) leaked a safe_fixtable hold when the coordinator was killed by an external signal. The table remained fixed for the lifetime of the node, preventing space reclamation of deleted objects.

  Own Id: OTP-20347
  Related Id(s): PR-11517

• Fixed a race condition where mnesia_controller could crash if a table was deleted while mnesia:set_master_nodes/2 was being processed.

  Own Id: OTP-20351
  Related Id(s): PR-11554

Full runtime dependencies of mnesia-4.25.3.2

erts-9.0, kernel-5.3, stdlib-5.0

snmp-5.20.2.2

The snmp-5.20.2.2 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• The SNMP PDU decoder now bounds the byte length accepted for INTEGER, Counter32, Gauge32/Unsigned32, TimeTicks, and Counter64 values during decoding (4, 5, 5, 5, and 9 bytes respectively, matching the SMIv2 value ranges), instead of accepting an arbitrarily large byte string and converting it to an integer.

  Own Id: OTP-20346
  Related Id(s): PR-11538

Full runtime dependencies of snmp-5.20.2.2

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

ssh-5.5.2.5

Note! The ssh-5.5.2.5 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-5.7 (first satisfied in OTP 28.1)

Fixed Bugs and Malfunctions

• Fixed a bug where multiple subsystem requests could succeed on same ssh channel which is forbidden by RFC 4254 §6.5

  Own Id: OTP-20284
  Related Id(s): PR-11437

Full runtime dependencies of ssh-5.5.2.5

crypto-5.7, erts-14.0, kernel-10.3, public_key-1.6.1, runtime_tools-1.15.1, stdlib-5.0, stdlib-6.0

ssl-11.6.0.5

Note! The ssl-11.6.0.5 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

• Debugging keylog_hs callback used for logging handshake secrets on failed connections swapped the argument order in logging function confusing server and client side. The bug was introduced in OTP 28.5

  Own Id: OTP-20350
  Related Id(s): ERIERL-1354, PR-11553

Improvements and New Features

• Hardening improvements of the ssl application.

  TLS distribution now defaults to TLS-1.3 instead of TLS-1.2 (TLS-1.2 is kept as fallback for rolling upgrades).

  TLS-1.2 server with {verify, verify_peer} now defaults reuse_sessions to false to mitigate the Triple Handshake attack (RFC 7627). Set {reuse_sessions, true} explicitly to restore previous behavior.

  Various missing or faulty sanity checks added and TLS alerts adjusted to comply with RFC MUST requirements, including: signature algorithm validation for intermediate certificates, TLS-1.3 session_id echo, pre_shared_key extension ordering, and renegotiation_info enforcement.

  Hardened and improved CRL support. Introduces new option allowed_hosts for the optional CRL HTTP fetching feature to restrict which hosts may be contacted. Internal/loopback IPs are now blocked by default (SSRF protection).

  TLS-1.3 client ticket handling is more robust (locked tickets are released on client crash). Server TLS-1.3 ticket handling and anti-replay Bloom filter performance are optimized.

  DTLS duplicate ChangeCipherSpec handling simplified, fixing potential state machine confusion (GH-11075).

  Process state formatting no longer leaks secrets in crash logs.

  Own Id: OTP-20289
  Related Id(s): PR-11478

Full runtime dependencies of ssl-11.6.0.5

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

stdlib-7.3.0.2

Note! The stdlib-7.3.0.2 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:
   -- erts-16.0.3 (first satisfied in OTP 28.0.3)

Fixed Bugs and Malfunctions

• Fixed a bug in unicode_util:gc/1 where the grapheme cluster segmentation of $\r (not followed by $\n) would decompose binary continuations into mixed chardata. This caused string:trim/3 (and string:chomp/1) to return incorrect results or crash when trimming strings containing binaries followed by another list element.

  Own Id: OTP-20296
  Related Id(s): GH-11380, PR-11464

• When compiling a module with a triple-quoted string with escape sequences and a chunk boundary happened to fall just after an escape character, that character was not passed to the reentrancy continuation, so the scanner interpreted the following characters as not an escape sequence.

  This bug has now been fixed.

  Own Id: OTP-20320
  Related Id(s): GH-11423, PR-11505

• uri_string:parse/1 now rejects URIs with an unreasonably long port component (more than 5 digits) instead of attempting to convert an arbitrarily large digit string to an integer.

  Own Id: OTP-20344
  Related Id(s): PR-11538

Full runtime dependencies of stdlib-7.3.0.2

compiler-5.0, crypto-4.5, erts-16.0.3, kernel-10.0, sasl-3.0, syntax_tools-3.2.1

tools-4.1.4.1

The tools-4.1.4.1 application can be applied independently of other applications on a full OTP 28 installation.

Fixed Bugs and Malfunctions

• tools: fixes tprof not stopping tracing

  A call to tprof:enable_trace(new|existing) starts tracing processes. To stop it, one calls tprof:disable_trace(new|existing). However, the guard to stop tracing was matching on new_processes | existing_processes. The return happens to say 0 processes are traced now, but the tracing did not stop. This issue has been fixed.

  Own Id: OTP-20302
  Related Id(s): PR-11481

Full runtime dependencies of tools-4.1.4.1

compiler-8.5, erts-15.0, erts-15.0, kernel-10.0, runtime_tools-2.1, stdlib-6.0

Thanks to

Andrew Bennett, Laurynas Četyrkinas, ruslandoga, Thomas Cioppettini