CVE-2026-65634Network attack vectorHinoki check available

CPU denial of service via oversized OID arcs

Published Sep 22, 2026 · Updated Sep 22, 2026

Inefficient OID decoding in affected Erlang/OTP releases allows remote attackers to interrupt services via crafted TLS certificates. The BER and PER dec_subidentifiers routines repeatedly shift and add base-128 continuation bytes into an unbounded integer, causing quadratic CPU work for one oversized OID arc. Reachability requires an Erlang service to parse an attacker-controlled certificate, as TLS clients and mutual-TLS servers do before trust verification; sustained inputs can exhaust CPU and interrupt service.

CVSS severityUnavailable
Unscored
EPSS probability0.27%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Inefficient OID decoding in affected Erlang/OTP releases allows remote attackers to interrupt services via crafted TLS certificates. The BER and PER dec_subidentifiers routines repeatedly shift and add base-128 continuation bytes into an unbounded integer, causing quadratic CPU work for one oversized OID arc. Reachability requires an Erlang service to parse an attacker-controlled certificate, as TLS clients and mutual-TLS servers do before trust verification; sustained inputs can exhaust CPU and interrupt service.

The record

CVE
CVE-2026-65634
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
Erlang
Product
Erlang/OTP
Classifications
CWE-407, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=17.0 <* changes=[{"at":"27.3.4.18","status":"unaffected"},{"at":"28.5.0.7","status":"unaffected"},{"at":"29.1.1","status":"unaffected"}]
  2. Affected versionversion=3.0 <* changes=[{"at":"5.3.4.3","status":"unaffected"},{"at":"5.4.3.1","status":"unaffected"},{"at":"5.5.2","status":"unaffected"}]
  3. Affected versionversion=84adefa331c4159d432d22840663c38f155cd4c1 <0fe2c02fdc06fab1c63be9db1a7456993d20f838

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Erlang · Erlang/OTPversion=17.0 <* changes=[{"at":"27.3.4.18","status":"unaffected"},{"at":"28.5.0.7","status":"unaffected"},{"at":"29.1.1","status":"unaffected"}]; version=3.0 <* changes=[{"at":"5.3.4.3","status":"unaffected"},{"at":"5.4.3.1","status":"unaffected"},{"at":"5.5.2","status":"unaffected"}]; version=84adefa331c4159d432d22840663c38f155cd4c1 <0fe2c02fdc06fab1c63be9db1a7456993d20f838

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-407Inefficient Algorithmic Complexity
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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