CVE-2026-54887Network attack vector

Source-address bypass via predictable DTLS cookie

Published Jul 2, 2026 · Updated Jul 2, 2026

Default-key use in affected Erlang/OTP ssl releases allows remote attackers to bypass DTLS source-address checks during server startup. dtls_server_connection:initial_hello/3 initializes previous_cookie_secret to an empty binary, so the observable ClientHello yields a predictable HMAC cookie until secret rotation. Exploitation requires observing that plaintext hello within the 0-to-15-second startup window and enables spoofed-source handshake amplification, not authentication bypass.

CVSS severity6.3
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Default-key use in affected Erlang/OTP ssl releases allows remote attackers to bypass DTLS source-address checks during server startup. dtls_server_connection:initial_hello/3 initializes previous_cookie_secret to an empty binary, so the observable ClientHello yields a predictable HMAC cookie until secret rotation. Exploitation requires observing that plaintext hello within the 0-to-15-second startup window and enables spoofed-source handshake amplification, not authentication bypass.

The record

CVE
CVE-2026-54887
Published
Jul 2, 2026
Updated
Jul 2, 2026
Vendor
Erlang
Product
Erlang/OTP
Classifications
CWE-1394, CAPEC-485, T1498.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 2, 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=20.0 <* changes=[{"at":"29.0.3","status":"unaffected"},{"at":"28.5.0.3","status":"unaffected"},{"at":"27.3.4.14","status":"unaffected"}]
  2. Affected versionversion=8.2 <* changes=[{"at":"11.7.3","status":"unaffected"},{"at":"11.6.0.3","status":"unaffected"},{"at":"11.2.12.10","status":"unaffected"}]
  3. Affected versionversion=e594aad2f87aab39e99fccf9e021bc94e0bbf7d4 <888e3bcd72d5406016b9e0de741026bc2a6f114d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Erlang · Erlang/OTPversion=20.0 <* changes=[{"at":"29.0.3","status":"unaffected"},{"at":"28.5.0.3","status":"unaffected"},{"at":"27.3.4.14","status":"unaffected"}]; version=8.2 <* changes=[{"at":"11.7.3","status":"unaffected"},{"at":"11.6.0.3","status":"unaffected"},{"at":"11.2.12.10","status":"unaffected"}]; version=e594aad2f87aab39e99fccf9e021bc94e0bbf7d4 <888e3bcd72d5406016b9e0de741026bc2a6f114d

Published CVSS scores

6.3Erlang Ecosystem FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
4.8NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1394Use of Default Cryptographic Key
CAPEC-485Signature Spoofing by Key Recreation
T1498.002Reflection Amplification

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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