CVE-2026-59251

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:eef, epss
Trending — 3 sources updated this week
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.7
EG Score
8.7(medium)
EG Risk
54(Track)
EG Risk 54/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

July 27, 2026

Last Modified

July 28, 2026

Advisory Details (6)

Auto-updated Jul 27, 2026
Patch available. Sources: github, github_commit.
github_commit

commit f04c6bba38de (erlang/otp)

Fix landed in erlang/otp commit f04c6bba38de — awaiting tagged release

https://github.com/erlang/otp/commit/f04c6bba38de1cf1b1836a7d9a9fbe239bd939e8
github_commit

commit f8580fc11709 (erlang/otp)

Fix landed in erlang/otp commit f8580fc11709 — awaiting tagged release

https://github.com/erlang/otp/commit/f8580fc117098c08165f46c26fd0750c5cfb2a90
generic

Versions — Erlang System Documentation v29.0.4

https://www.erlang.org/doc/system/versions.html#order-of-versions
generic

OSV - Open Source Vulnerabilities

https://osv.dev/vulnerability/EEF-CVE-2026-59251
generic

Denial of service via exponential certificate policy tree growth in path validation | Erlang Ecosystem Foundation CNA

https://cna.erlef.org/cves/CVE-2026-59251.html
github Patch Available

Denial of Service via Exponential Certificate Policy Tree Growth · Advisory · erlang/otp · GitHub

https://github.com/erlang/otp/security/advisories/GHSA-622p-qfh6-c352

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-28 22:09 UTCEG score recompute
  2. 2026-07-28 15:37 UTCEPSS rescore
  3. 2026-07-28 10:16 UTCEG score recompute
  4. 2026-07-27 19:30 UTCEG score recompute
  5. 2026-07-27 19:06 UTCEG score recompute
  6. 2026-07-27 16:24 UTCEG score recompute
  7. 2026-07-27 16:16 UTCEG score recompute
  8. 2026-07-27 16:16 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-59251?
CVE-2026-59251 is a high vulnerability published on July 27, 2026. 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 publickey:pkixpathvalidation/3,…
When was CVE-2026-59251 disclosed?
CVE-2026-59251 was first published in the National Vulnerability Database on July 27, 2026, with the most recent update on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59251 actively exploited?
CVE-2026-59251 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 82.3% of all scored CVEs.
What is the CVSS score of CVE-2026-59251?
CVE-2026-59251 has a CVSS v4.0 base score of 8.7 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-59251?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59251, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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