Cyber Resilience

CVE-2026-54887

Erlang\/Otp 20.0 – 27.3.4.14

Published
02 July 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v4 6.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/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
EPSS Score 0.0024 15th percentile
Risk Priority 40 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-54887 is a medium-severity Use of Default Cryptographic Key (CWE-1394) vulnerability in Erlang Erlang\/Otp. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Private Keys (T1552.004); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and SC-12 (Cryptographic Key Establishment and Management) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Use of Default Cryptographic Key vulnerability in Erlang/OTP ssl (DTLS server) allows predictable DTLS cookie computation during the startup window, enabling source address verification bypass. On DTLS server startup, dtls_server_connection:initial_hello/3 initializes previous_cookie_secret to the empty binary (<<>>) instead of a…

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random value. Because HMAC with an empty key is deterministic, anyone who observes the plaintext ClientHello can compute dtls_handshake:cookie(<<>>, IP, Port, Hello) and forge a valid DTLS cookie before the first rotation of the cookie secret. The DTLS cookie (RFC 6347 §4.2.1) is a denial-of-service mitigation that prevents spoofed source IPs from forcing the server to allocate state and perform expensive cryptographic operations; it is not an authentication mechanism. During the window from server startup until the first secret rotation (0 to 15 seconds), an attacker who can observe the plaintext ClientHello can bypass the source address verification, enabling DTLS handshake amplification with spoofed source addresses. This vulnerability is associated with program file lib/ssl/src/dtls_server_connection.erl and program routine dtls_server_connection:initial_hello/3. This issue affects OTP from OTP 20.0 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssl from 8.2 before 11.7.3, 11.6.0.3 and 11.2.12.10.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-58227Same product: Erlang Erlang\/Otp
CVE-2026-48860Same product: Erlang Erlang\/Otp
CVE-2026-55953Same product: Erlang Erlang\/Otp
CVE-2026-55950Same product: Erlang Erlang\/Otp
CVE-2026-54891Same product: Erlang Erlang\/Otp
CVE-2026-55952Same product: Erlang Erlang\/Otp
CVE-2026-32144Same product: Erlang Erlang\/Otp
CVE-2026-42790Same product: Erlang Erlang\/Otp
CVE-2026-42789Same product: Erlang Erlang\/Otp
CVE-2026-28810Same product: Erlang Erlang\/Otp

Affected Assets

erlang
erlang\/otp
20.0 — 27.3.4.14 · 28.0 — 28.5.0.3 · 29.0 — 29.0.3
erlang
erlang\/ssl
8.2 — 11.2.12.10 · 11.3 — 11.6.0.3 · 11.7 — 11.7.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Cryptographic key establishment and management requires generating and provisioning unique keys rather than relying on manufacturer defaults.

Requiring the most restrictive configuration settings prohibits the use of known default cryptographic keys.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-01 mostly match
prevents

Configuration management directly prohibits default keys via hardened baselines and change control.

PR.AA-01 partial match
prevents

Credential/key management practices eliminate default cryptographic keys for identities and services.

PR.AA-03 partial match
prevents

Strong authentication requirements implicitly disallow default keys but do not address key management itself.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Mandates proper key management, directly preventing use of default cryptographic keys.

prevents

Enforces secure configuration baselines that should replace default keys.

prevents

Controls software installation and configuration, reducing risk of default keys being left in place.

prevents

Change-management processes should detect and remediate default cryptographic keys.

References