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CVE-2026-59251· NVD / CVE Program· CNA EEF

Denial of service via exponential certificate policy tree growth in path validation

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.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Jul 27, 2026
Updated
Aug 10, 2026
EPSS
0.5% · 42th percentile
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Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · EEF
8.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
erlangerlang\/otp
erlangerlang\/public key

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • erlang erlang/otp26.2 and later · before 27.3.4.15
  • erlang erlang/otp28.0 and later · before 28.5.0.4
  • erlang erlang/otp29.0 and later · before 29.0.4
  • erlang erlang/public key1.15 and later · before 1.17.1.5
  • erlang erlang/public key1.18 and later · before 1.20.3.4
  • erlang erlang/public key1.21 and later · before 1.21.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.

  • Erlang OTP

    • 1.15 and lateraffected · otpfixed in 1.21.4, 1.20.3.4, 1.17.1.5
    • 26.2 and lateraffected · otpfixed in 29.0.4, 28.5.0.4, 27.3.4.15
    • 9d1dda7bad5a64b58c10a1554751689e94131a73 and lateraffected · gitfixed in f8580fc117098c08165f46c26fd0750c5cfb2a90, f04c6bba38de1cf1b1836a7d9a9fbe239bd939e8

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12erlangall versions—
Debian:13erlangbefore 1:27.3.4.1+dfsg-1+deb13u31:27.3.4.1+dfsg-1+deb13u3
Debian:14erlangbefore 1:29.0.4+dfsg-11:29.0.4+dfsg-1
Red Hat:hummingbird:1erlang27before 0:27.3.4.15-0.1.hum10:27.3.4.15-0.1.hum1

Same product

erlang: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-32433Erlang/OTP SSH Vulnerable to Pre-Authentication RCEKEV
    100Now
  • CVE-2022-37026In Erlang/OTP before 23.3.4.15, 24.x before 24.3.4.2, and 25.x before 25.0.2, there is a Client Authentication Bypass in certain client-cert
    39Monitor
  • CVE-2016-10253An issue was discovered in Erlang/OTP 18.x.
    39Monitor
  • CVE-2026-55953TLS 1.2 and DTLS client accepts unoffered anonymous cipher suite, bypassing server authentication
    36Monitor
  • CVE-2026-49759Stack buffer overflow in SCTP error cause parsing in inet_drv allows remote VM crash
    35Monitor
  • CVE-2026-58227TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate chain
    34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Erlang OTP1.17.1.5Vendor (CNA)
Erlang OTP1.20.3.4Vendor (CNA)
Erlang OTP1.21.4Vendor (CNA)
Erlang OTP27.3.4.15Vendor (CNA)
Erlang OTP28.5.0.4Vendor (CNA)
Erlang OTP29.0.4Vendor (CNA)
Erlang OTPf04c6bba38de1cf1b1836a7d9a9fbe239bd939e8Vendor (CNA)
Erlang OTPf8580fc117098c08165f46c26fd0750c5cfb2a90Vendor (CNA)
Debian:erlang1:27.3.4.1+dfsg-1+deb13u3 · Debian:13Package registry (OSV)
Red Hat:erlang270:27.3.4.15-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-770 · Allocation of Resources Without Limits or Throttling

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records