Erlang OTP vulnerabilities

64 vulnerabilities

Known vulnerabilities in Erlang OTP, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.

5.9CVE-2026-96596debianerlang+7
EPSS score
0.18%
Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib (erl_tar module), hexpm hex_core (hex_erl_tar module), hexpm hex (mix_hex_erl_tar module) and erlang rebar3 (r3_hex_erl_tar module) allows an attacker who supplies a tar archive to cause a denial of service via a crafted GNU sparse member. When erl_tar:extract/1,2 writes a member to disk, erl_tar:stream_to_file_loop/3 reads it in chunks of 65536 bytes by default. For a GNU sparse member whose sparse map ends before its real size, erl_tar:do_sparse_read/3 matches its trailing-hole clause before its zero-length clause. After the chunk is used up, the trailing-hole clause reads zero bytes, does not advance the position, and recurses forever. A 2048-byte archive keeps the extracting process and one scheduler busy until the process is killed. The {max_size, N} option prevents this only when N is below the real size of the member. Extraction with the memory option is not affected. hex_core ships its own copy of erl_tar as hex_erl_tar, and Hex and rebar3 ship hex_core with prefixed module names (mix_hex_erl_tar and r3_hex_erl_tar). These copies contain the same code and do not call stdlib's erl_tar, so they are affected on any OTP version. OTP 28 is not affected, but an application running on OTP 28 is affected if it extracts archives through an affected version of hex_core, Hex or rebar3. This issue affects OTP from OTP 29.0 before OTP 29.1.2, corresponding to stdlib from 8.0 before 8.1.1, and rebar3 from 3.27.1 onward, and hex from 2.4.2 before 2.5.3; hex_core: from 0.14.0 before 0.20.1.
8.2CVE-2026-94200debianerlang+2
EPSS score
0.47%
Improper Validation of Consistency within Input vulnerability in Erlang OTP ssl (tls_handshake_1_3, ssl_handshake and tls_client_ticket_store modules) allows a malicious TLS 1.3 server to cause a denial of service of the ssl application on the client node. The TLS 1.3 client decodes the extensions of a NewSessionTicket message as if they came from EncryptedExtensions. It therefore accepts a 0-length early_data extension, a form that is only valid in ClientHello and EncryptedExtensions. With {session_tickets, auto}, the client stores the ticket in the node-global tls_client_ticket_store. On the next automatic resumption, tls_handshake_1_3:get_max_early_data/1 crashes the store with a case_clause. Repeated crashes can exceed the restart intensity of the ssl supervisors, which use the rest_for_one strategy, and take down ssl for all connections on the node. This issue affects OTP from OTP 23.3 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to ssl from 10.3 before 11.2.12.14, 11.6.0.7, and 11.7.8.
6.3CVE-2026-105236debianerlang+2
EPSS score
0.36%
Improper Certificate Validation vulnerability in the ssl application in Erlang/OTP allows a client that holds a certificate trusted by one SNI virtual host to authenticate to a second SNI virtual host on the same listener by resuming its TLS 1.2 session there. A server that serves several SNI names from one listen socket through sni_fun or sni_hosts keeps one pre-TLS 1.3 session cache per listener and does not bind a cached session to the SNI name or client trust policy that established it. When an SNI option set switches to verify_peer without naming reuse_sessions, ssl_config:update_options/3 inherits the base listener's reuse_sessions value of true, so the default that disables reuse for client-authenticating servers does not apply. On an abbreviated handshake ssl_session:is_resumable/4 checks only that the cached session uses one of the current server certificates and carries some peer certificate, and never revalidates that certificate against the CA selected for the requested name. The names must share a server certificate, which is common with wildcard or multi-SAN certificates. TLS 1.3 does not use this cache and is not affected. This issue affects OTP from OTP 18.0 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to ssl from 7.0 before 11.2.12.14, 11.6.0.7, and 11.7.8.
7CVE-2025-26618debianerlang+8
EPSS score
0.50%
Erlang is a programming language and runtime system for building massively scalable soft real-time systems with requirements on high availability. OTP is a set of Erlang libraries, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang. Packet size is not verified properly for SFTP packets. As a result when multiple SSH packets (conforming to max SSH packet size) are received by ssh, they might be combined into an SFTP packet which will exceed the max allowed packet size and potentially cause large amount of memory to be allocated. Note that situation described above can only happen for successfully authenticated users after completing the SSH handshake. This issue has been patched in OTP versions 27.2.4, 26.2.5.9, and 25.3.2.18. There are no known workarounds for this vulnerability.
5.3CVE-2025-48039debianerlang+2
EPSS score
0.39%
Allocation of Resources Without Limits or Throttling vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Resource Leak Exposure. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP from OTP 17.0 before OTP 28.0.3, OTP 27.3.4.3 and OTP 26.2.5.15, corresponding to ssh from 3.0.1 before 5.3.3, 5.2.11.3 and 5.1.4.12.
5.3CVE-2025-48038debianerlang+2
EPSS score
0.39%
Allocation of Resources Without Limits or Throttling vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Resource Leak Exposure. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP from OTP 17.0 before OTP 28.0.3, OTP 27.3.4.3 and OTP 26.2.5.15, corresponding to ssh from 3.0.1 before 5.3.3, 5.2.11.3 and 5.1.4.12.
6.9CVE-2025-48040debianerlang+2
EPSS score
0.43%
Uncontrolled Resource Consumption vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Flooding. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP from OTP 17.0 before OTP 28.0.3, OTP 27.3.4.3 and OTP 26.2.5.15, corresponding to ssh from 3.0.1 before 5.3.3, 5.2.11.3 and 5.1.4.12.
7.1CVE-2025-48041debianerlang+22
EPSS score
0.39%
Allocation of Resources Without Limits or Throttling vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Flooding. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP from OTP 17.0 before OTP 28.0.3, OTP 27.3.4.3 and OTP 26.2.5.15, corresponding to ssh from 3.0.1 before 5.3.3, 5.2.11.3 and 5.1.4.12.
4.8CVE-2025-4748debianerlang+8
EPSS score
0.29%
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (stdlib modules) allows Absolute Path Traversal, File Manipulation. This vulnerability is associated with program files lib/stdlib/src/zip.erl and program routines zip:unzip/1, zip:unzip/2, zip:extract/1, zip:extract/2 unless the memory option is passed. This issue affects OTP from OTP 17.0 before OTP 28.0.1, OTP 27.3.4.1 and OTP 26.2.5.13, corresponding to stdlib from 2.0 before 7.0.1, 6.2.2.1 and 5.2.3.4.
3.7CVE-2025-46712debianerlang+2
EPSS score
0.54%
Erlang/OTP is a set of libraries for the Erlang programming language. In versions prior to OTP-27.3.4 (for OTP-27), OTP-26.2.5.12 (for OTP-26), and OTP-25.3.2.21 (for OTP-25), Erlang/OTP SSH fails to enforce strict KEX handshake hardening measures by allowing optional messages to be exchanged. This allows a Man-in-the-Middle attacker to inject these messages in a connection during the handshake. This issue has been patched in versions OTP-27.3.4 (for OTP-27), OTP-26.2.5.12 (for OTP-26), and OTP-25.3.2.21 (for OTP-25).
10CVE-2025-32433ciscocloud_native_broadband_network_gateway+41KEV
EPSS score
98.79%
Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20, a SSH server may allow an attacker to perform unauthenticated remote code execution (RCE). By exploiting a flaw in SSH protocol message handling, a malicious actor could gain unauthorized access to affected systems and execute arbitrary commands without valid credentials. This issue is patched in versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20. A temporary workaround involves disabling the SSH server or to prevent access via firewall rules.
7.5CVE-2025-30211debianerlang+2
EPSS score
0.46%
Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option `parallel_login` to `false` and/or reduce the `max_sessions` option.
5.5CVE-2024-53846debianerlang+2
EPSS score
0.26%
OTP is a set of Erlang libraries, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang, and a set of design principles for Erlang programs. A regression was introduced into the ssl application of OTP starting at OTP-25.3.2.8, OTP-26.2, and OTP-27.0, resulting in a server or client verifying the peer when incorrect extended key usage is presented (i.e., a server will verify a client if they have server auth ext key usage and vice versa).
2.3CVE-2026-21620debianerlang+2
EPSS score
0.52%
Relative Path Traversal, Improper Isolation or Compartmentalization vulnerability in erlang otp erlang/otp (tftp_file modules), erlang otp inets (tftp_file modules), erlang otp tftp (tftp_file modules) allows Relative Path Traversal. This vulnerability is associated with program files lib/tftp/src/tftp_file.erl, src/tftp_file.erl. This issue affects OTP from OTP 17.0 before OTP 28.3.2, OTP 27.3.4.8 and OTP 26.2.5.17, corresponding to tftp from 1.0 before 1.2.4, 1.2.2.1 and 1.1.1.1; also inets from 5.10 before 7.0.
8.7CVE-2026-74835debianerlang+2
EPSS score
0.58%
The inets application HTTP server httpd fails to enforce a configured body-size limit on chunked request. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
6CVE-2026-74994debianerlang+2
EPSS score
0.63%
The mod_auth module in OTP's inets httpd server, when configured with dets or mnesia authentication backends and multiple directory configuration blocks, collapses all directory blocks into a single shared user/group namespace. A user added to one protected directory is accepted as valid for all other protected directories on the same server instance. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.
6.3CVE-2026-54887debianerlang+4
EPSS score
0.24%
Use of Default Cryptographic Key vulnerability in Erlang/OTP ssl (DTLS server) allows predictable DTLS cookie computation during the startup window, enabling source address verification bypass. On DTLS server startup, dtls_server_connection:initial_hello/3 initializes previous_cookie_secret to the empty binary (<<>>) instead of a random value. Because HMAC with an empty key is deterministic, anyone who observes the plaintext ClientHello can compute dtls_handshake:cookie(<<>>, IP, Port, Hello) and forge a valid DTLS cookie before the first rotation of the cookie secret. The DTLS cookie (RFC 6347 §4.2.1) is a denial-of-service mitigation that prevents spoofed source IPs from forcing the server to allocate state and perform expensive cryptographic operations; it is not an authentication mechanism. During the window from server startup until the first secret rotation (0 to 15 seconds), an attacker who can observe the plaintext ClientHello can bypass the source address verification, enabling DTLS handshake amplification with spoofed source addresses. This vulnerability is associated with program file lib/ssl/src/dtls_server_connection.erl and program routine dtls_server_connection:initial_hello/3. This issue affects OTP from OTP 20.0 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssl from 8.2 before 11.7.3, 11.6.0.3 and 11.2.12.10.
6.3CVE-2026-54891debianerlang+4
EPSS score
0.14%
Improper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerability in Erlang/OTP ssl (tls_gen_connection module) allows a network-positioned attacker to inject unauthenticated plaintext that the TLS client application later treats as authenticated server data. The function tls_gen_connection:handle_protocol_record/3 rejects APPLICATION_DATA records that arrive in pre-handshake states when the TLS endpoint acts as a server, but does not apply the same check when the endpoint acts as a client. A network-positioned attacker can send plaintext APPLICATION_DATA records to the client during the handshake. The records are buffered and, once the handshake completes successfully, delivered to the application as if they were authenticated post-handshake data. The attacker cannot observe the client's response or steer the connection, so the impact is limited to blind injection of unauthenticated bytes. The injection window is wider for TLS versions prior to TLS 1.3 than for TLS 1.3. This vulnerability is associated with program file lib/ssl/src/tls_gen_connection.erl. TLS 1.3 is affected starting with OTP 22.0, when TLS 1.3 support was added. This issue affects OTP from OTP 17.0 before OTP 27.3.4.14, from OTP 28.0 before OTP 28.5.0.3, and from OTP 29.0 before OTP 29.0.3, corresponding to ssl from 5.3.4 before 11.2.12.10, from 11.3 before 11.6.0.3, and from 11.7 before 11.7.3. Whether OTP before OTP 17.0, corresponding to ssl before 5.3.4, is affected is unknown.
5.3CVE-2026-54886debianerlang+4
EPSS score
0.33%
Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to render an SFTP channel permanently unresponsive. The handle_data/4 function in ssh_sftpd contains a catch-all clause that accepts channel data of any type. When channel data with a non-zero type code (SSH_MSG_CHANNEL_EXTENDED_DATA) arrives with an empty pending buffer and a payload at or below the SFTP packet size limit, the clause tail-calls itself with identical arguments, creating an infinite loop. The SFTP protocol operates exclusively on normal channel data (type 0). Extended data (non-zero type) is meaningless for SFTP and is never sent by conforming clients. However, the SSH protocol permits any channel participant to send extended data on an open channel, so an authenticated SFTP client can trigger the loop by sending SSH_MSG_CHANNEL_EXTENDED_DATA with any data_type_code and any non-empty payload at or below the size limit. The targeted ssh_sftpd process enters an infinite tail-recursive loop. It never processes another message, its message queue grows without bound, and it can only be stopped by killing the process. BEAM's reduction-based scheduler preemption continues to function, so other processes on the node are not starved, but each stuck channel process consumes its full CPU time share continuously and accumulates unbounded message queue memory. Opening many channels amplifies the CPU and memory impact. Erlang/OTP SSH configurations using the default max_channels setting (infinity) allow an authenticated user to open unlimited channels per connection, amplifying the attack without requiring multiple TCP connections or authentications. No file contents, credentials, or write access are obtainable through this issue. The impact is limited to denial of service on targeted SFTP channels, with secondary CPU degradation and memory growth. This vulnerability is associated with program file lib/ssh/src/ssh_sftpd.erl and program routine ssh_sftpd:handle_data/4. This issue affects OTP from OTP 17.0 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssh from 3.0.1 before 6.0.2, 5.5.2.2 and 5.2.11.9.
8.2CVE-2026-54890debianerlang+4
EPSS score
0.42%
Integer Underflow (Wrap or Wraparound) vulnerability in erlang otp erlang/otp (erts modules), erlang otp erts (erts modules) allows Forced Integer Overflow, Excessive Allocation. This vulnerability is associated with program files erts/emulator/beam/external.c, emulator/beam/external.c. The BIT_BINARY_EXT tag (77) handler in the External Term Format (ETF) decoder accepts an encoding with both length and trailing-bits fields set to zero. The subsequent computation of the bitstring size underflows an unsigned integer, producing a value of roughly 2^64 that is then passed as a memory allocation size. The allocator aborts the entire node with a message such as "Cannot allocate 2305843009213693951 bytes of memory (of type binary)". The crash is a VM-level abort, not an Erlang-level exception. It cannot be intercepted by supervision trees, by try/catch, or by passing the [safe] option to binary_to_term/2 (which only restricts atom creation and does not perform structural validation of binary encodings). Any application that decodes ETF from untrusted sources via binary_to_term/1,2 or enif_binary_to_term() is exposed. The Erlang distribution protocol also decodes incoming terms through the same code path, but distribution is expected to run on trusted networks per the OTP Secure Coding Guidelines (DSG-011). This issue affects OTP from OTP 27.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to erts from 15.0 before 17.0.4, 16.4.0.4 and 15.2.7.11.