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.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6464 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6464-1                   security@debian.org     https://www.debian.org/security/                                  Aron Xu     August 25, 2026                       https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : erlang     CVE ID         : CVE-2026-28808 CVE-2026-28810 CVE-2026-32144 CVE-2026-32147                      CVE-2026-42789 CVE-2026-42790 CVE-2026-42791 CVE-2026-42792                      CVE-2026-47078 CVE-2026-48855 CVE-2026-48856 CVE-2026-48858                      CVE-2026-48860 CVE-2026-49759 CVE-2026-49760 CVE-2026-53422                      CVE-2026-54886 CVE-2026-54887 CVE-2026-54890 CVE-2026-54891                      CVE-2026-55737 CVE-2026-55950 CVE-2026-55952 CVE-2026-55953                      CVE-2026-58227 CVE-2026-59250 CVE-2026-59251     Debian Bug     : 1139727 1139823 1141414 1142985

    Multiple vulnerabilities were discovered in Erlang/OTP, a concurrent,     real-time, distributed functional language, which may result in denial of     service, information disclosure, authentication and certificate validation     bypass, or the execution of arbitrary code. These vulnerbilities affect a     wide range of components: TLS and certificate validation (ssl, public_key),     SSH (ssh), network clients and servers (inets, ftp, epmd, kernel),     runtime and libraries (erts, erl_interface, stdlib, megaco).

    Several of these fixes tighten checks that were previously too permissive,     and can cause configurations that worked before to stop working. The most     likely to be noticed are:

     - TLS clients using verify_peer, which is the default, now reject        certificates that carry no subjectAltName extension; the        customize_hostname_check option does not restore the old behaviour.

     - Erlang distribution over TLS with the kernel 'check_ip' option now        enforces the check that was previously a no-op, so clusters whose nodes        are not on the same subnet lose distribution connectivity until the        option is unset.

     - TLS clients that request OCSP stapling now fail the handshake when the        server provides no stapled response.

     - Clients using TLS 1.2 or earlier now abort the handshake if the server        sends an ALPN extension that the client did not advertise.

     - DNS queries made through inet_res now use randomised source ports

    For the stable distribution (trixie), these problems have been fixed in     version 1:27.3.4.1+dfsg-1+deb13u3.

    We recommend that you upgrade your erlang packages.

    For the detailed security status of erlang please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/erlang

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the erlang package has been released.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3579-1 advisory.

    - 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).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Erlang/OTP installed on the remote host is 26.2 prior to 27.3.4.15, 28.0 prior to 28.5.0.4, or 29.0 prior to 29.0.4. It is, therefore, affected by a vulnerability:

  - 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, the certificate     policy tree grows without an upper bound. 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.
    (CVE-2026-59251)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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.
    (CVE-2026-59251)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 445d674f-89e1-11f1-b35c-4c526214c986 advisory.

    https://github.com/erlang/otp/security/advisories/GHSA-622p-qfh6-c352 reports:
    A remote attacker can trigger a denial of service through               TLS certificate handling. By sending a specially crafted               certificate chain with multiple certificate policies at each               level, the policy tree expands exponentially during validation,               growing as M^K nodes (where M is the number of policies per               certificate and K is the chain depth). This pins schedulers               and exhausts memory without any authentication. Any               application using SSL/TLS that validates certificate paths is               affected, as are direct calls to               public_key:pkix_path_validation/3.

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Type	Severity
339216	Debian dsa-6464 : erlang - security update	Nessus	Debian Local Security Checks	Local	critical
338673	Photon OS 5.0: Erlang PHSA-2026-5.0-92-0958	Nessus	PhotonOS Local Security Checks	Local	critical
335097	SUSE SLES15 Security Update : erlang26 (SUSE-SU-2026:3579-1)	Nessus	SuSE Local Security Checks	Local	critical
331346	Erlang/OTP 26.2 < 27.3.4.15 / 28.0 < 28.5.0.4 / 29.0 < 29.0.4 Policy Tree DoS (CVE-2026-59251)	Nessus	Misc.	Local	high
330394	Linux Distros Unpatched Vulnerability : CVE-2026-59251	Nessus	Misc.	Local	high
330272	FreeBSD : Erlang/OTP -- denial of service via exponential certificate policy tree growth (445d674f-89e1-11f1-b35c-4c526214c986)	Nessus	FreeBSD Local Security Checks	Local	high

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CVE-2026-59251

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Tenable Plugins

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