CVE-2026-59251

NameCVE-2026-59251
DescriptionAllocation 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
erlang (PTS)bullseye1:23.2.6+dfsg-1+deb11u1vulnerable
bullseye (security)1:23.2.6+dfsg-1+deb11u4vulnerable
bookworm1:25.2.3+dfsg-1+deb12u4vulnerable
bookworm (security)1:25.2.3+dfsg-1+deb12u1vulnerable
trixie1:27.3.4.1+dfsg-1+deb13u2vulnerable
forky, sid1:29.0.3+dfsg-1vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
erlangsource(unstable)(unfixed)

Notes

https://github.com/erlang/otp/security/advisories/GHSA-622p-qfh6-c352
https://cna.erlef.org/cves/CVE-2026-59251.html
https://osv.dev/vulnerability/EEF-CVE-2026-59251
Introduced with: https://github.com/erlang/otp/commit/9d1dda7bad5a64b58c10a1554751689e94131a73 (OTP-26.2)
Fixed by: https://github.com/erlang/otp/commit/f04c6bba38de1cf1b1836a7d9a9fbe239bd939e8 (OTP-27.3.4.15)
Fixed by: https://github.com/erlang/otp/commit/f8580fc117098c08165f46c26fd0750c5cfb2a90 (OTP-29.0.4, OTP-28.5.0.4)

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