CVE-2026-59251

Allocation of resources without limits in Erlang/OTP public_key certificate path validation allows a remote unauthenticated attacker to cause denial of service by sending a crafted X.509 certificate chain during the TLS handshake. During RFC 5280 policy processing in public_key:pkix_path_validation/3, the certificate policy tree maintained by pubkey_policy_tree grows without an upper bound. When a certificate chain contains M policies per certificate and K certificates, the tree grows on the order of M^K nodes because pubkey_policy_tree:add_leaves/2 and pubkey_policy_tree:add_leaf_siblings/2 extend the tree per policy per certificate. A modest chain with many policies per certificate is enough to pin BEAM schedulers and exhaust the node's memory, taking down the entire VM. The attacker only needs to be able to present a certificate chain to the victim, which is the normal precondition for a TLS handshake, so exploitation succeeds against any incoming or outgoing TLS connection that validates the peer's chain (the default for SSL/TLS clients and mutual-TLS servers). This is the same vulnerability class as OpenSSL's X509_verify_cert policy tree DoS. This vulnerability is associated with program files lib/public_key/src/pubkey_policy_tree.erl and program routines pubkey_policy_tree:add_leaves/2 and pubkey_policy_tree:add_leaf_siblings/2. This issue affects OTP from OTP 26.2 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to public_key from 1.15 before 1.21.4, 1.20.3.4 and 1.17.1.5.

Allocation of resources without limits in Erlang/OTP public_key certificate path validation allows a remote unauthenticated attacker to cause denial of service by sending a crafted X.509 certificate chain during the TLS handshake.

During RFC 5280 policy processing in public_key:pkix_path_validation/3, the certificate policy tree maintained by pubkey_policy_tree grows without an upper bound. When a certificate chain contains M policies per certificate and K certificates, the tree grows on the order of M^K nodes because pubkey_policy_tree:add_leaves/2 and pubkey_policy_tree:add_leaf_siblings/2 extend the tree per policy per certificate. A modest chain with many policies per certificate is enough to pin BEAM schedulers and exhaust the node's memory, taking down the entire VM. The attacker only needs to be able to present a certificate chain to the victim, which is the normal precondition for a TLS handshake, so exploitation succeeds against any incoming or outgoing TLS connection that validates the peer's chain (the default for SSL/TLS clients and mutual-TLS servers).

This is the same vulnerability class as OpenSSL's X509_verify_cert policy tree DoS.

This vulnerability is associated with program files lib/public_key/src/pubkey_policy_tree.erl and program routines pubkey_policy_tree:add_leaves/2 and pubkey_policy_tree:add_leaf_siblings/2.

This issue affects OTP from OTP 26.2 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to public_key from 1.15 before 1.21.4, 1.20.3.4 and 1.17.1.5.

These are all security issues fixed in the erlang-28.5.0.4-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the erlang27-27.1.3-3.1 package on the GA media of openSUSE Tumbleweed.

This update for erlang26 fixes the following issues:

• CVE-2026-28810: predictable DNS transaction IDs can cause DNS cache poisoning (bsc#1261726).
• CVE-2026-42789: public_key application accepts non-CA certificates as intermediate issuers and this enables chain forgery (bsc#1266449).
• CVE-2026-42790: Name constraints and Subject CommonName fallback in TLS hostname verification allows for certificate forgery by MITM attacker (bsc#1266466).
• CVE-2026-42792: permanent epmd DoS via connection slot exhaustion due to improper handling of exceptional conditions (bsc#1272908).
• CVE-2026-47078: relative path traversal in zip:unzip/zip:extract via check_dir_level depth-counter bypass (bsc#1272909).
• CVE-2026-48855: SFTP READLINK response leaks absolute backend filesystem path when root is configured (bsc#1268139).
• CVE-2026-48856: httpc leaks Authorization headers to cross-origin redirect targets (bsc#1268141).
• CVE-2026-48858: server-side request forgery allows FTP bounce attacks and SSRF via an unvalidated PASV response IP address (bsc#1268142).
• CVE-2026-48860: ssl (inet_tls_dist module) allows unauthenticated bypass of the distribution-over-TLS LAN allowlist (bsc#1268146).
• CVE-2026-49759: unbounded stack buffer overflow in SCTP error cause parsing in inet_drv (bsc#1268163).
• CVE-2026-49760: stack buffer overflow in ei_s_print_term at very large integer (bsc#1268164).
• CVE-2026-53422: SFTP REALPATH path-existence oracle allows filesystem enumeration outside configured root (bsc#1270245).
• CVE-2026-54886: SSH SFTP server denial of service via extended channel data infinite loop (bsc#1270246).
• CVE-2026-54887: use of default cryptographic key allows predictable DTLS cookie computation during the startup window (bsc#1270247).
• CVE-2026-54891: plaintext injection towards (D)TLS client during handshake (bsc#1270250).
• CVE-2026-55737: heap pointer corruption via signed/unsigned mismatch in LARGE_TUPLE_EXTP decoding in erts external term format decoder (bsc#1272910).
• CVE-2026-55950: time-of-check time-of-use race condition allows an unauthenticated remote attacker to crash all active DTLS sessions on a listener (bsc#1270253).
• CVE-2026-55952: missing validation allows for DoS of the TLS-1.3 server when clients send a malformed ClientHello with mismatched PSK identity and binder list lengths (bsc#1270258).
• CVE-2026-55953: TLS 1.2 and DTLS clients accept unoffered anonymous cipher suites and allow for server authentication bypass (bsc#1272911).
• CVE-2026-58227: TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate chain (bsc#1272913).
• CVE-2026-59250: megaco flex scanner buffer overflow via oversized property parm name (bsc#1272914).
• CVE-2026-59251: denial of service via exponential certificate policy tree growth in path validation (bsc#1272915).

It was discovered that the Erlang Port Mapper Daemon did not properly handle slow connections. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-42792)

It was discovered that Erlang incorrectly handled certain external term format data, leading to heap corruption. An attacker could possibly use this issue to cause Erlang to crash, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-55737)

It was discovered that Erlang incorrectly handled invalid external term format data. An attacker could possibly use this issue to cause Erlang to crash, resulting in a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-54890)

It was discovered that Erlang incorrectly handled certain packet lengths, leading to a buffer overflow. A remote attacker could possibly use this issue to cause Erlang to crash or execute arbitrary code. (CVE-2026-75538)

It was discovered that the Erlang Megaco flex scanner incorrectly handled certain input, leading to a buffer overflow. A remote attacker could possibly use this issue to cause Erlang to crash or execute arbitrary code. (CVE-2026-59250)

It was discovered that Erlang TLS clients incorrectly accepted cipher suites that they had not offered. A remote attacker could possibly use this issue to intercept and modify TLS communications. (CVE-2026-55953)

It was discovered that Erlang incorrectly handled certain certificate chains. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-58227)

It was discovered that Erlang incorrectly handled certain certificate policies. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-59251)

It was discovered that the Erlang HTTP server incorrectly handled certain conflicting HTTP framing headers. A remote attacker could possibly use this issue to smuggle HTTP requests. (CVE-2026-23941, CVE-2026-73812)

It was discovered that the Erlang HTTP server incorrectly handled certain malformed chunk sizes. A remote attacker could possibly use this issue to cause Erlang to crash, resulting in a denial of service. (CVE-2026-69664)

It was discovered that the Erlang HTTP server did not properly limit the size of chunked request bodies. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. (CVE-2026-74835)

It was discovered that the Erlang HTTP server incorrectly handled certain equivalent request paths and differences in character case. A remote attacker could possibly use this issue to bypass authentication and gain unauthorized access. (CVE-2026-66835, CVE-2026-73270)

It was discovered that the Erlang HTTP server did not properly limit simultaneous connections. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-70399)

It was discovered that the Erlang HTTP server incorrectly handled header continuation lines. A remote attacker could possibly use this issue to smuggle HTTP requests. (CVE-2026-66357)

It was discovered that the Erlang HTTP server incorrectly handled certain malformed header names. A remote attacker could possibly use this issue to smuggle HTTP requests. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-73276)

It was discovered that the Erlang HTTP server incorrectly handled incomplete request bodies. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of…