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 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 29.0.3, 28.5.0.3 and 27.3.4.14 corresponding to ssl from 8.2 before 11.7.3, 11.6.0.3 and 11.2.12.10.
References
| Link | Resource |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-54887.html | Vendor Advisory |
| https://github.com/erlang/otp/commit/888e3bcd72d5406016b9e0de741026bc2a6f114d | Patch |
| https://github.com/erlang/otp/security/advisories/GHSA-p2m2-3c2w-8jp8 | Vendor Advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-54887 | Third Party Advisory |
| https://www.erlang.org/doc/system/versions.html#order-of-versions | Release Notes |
Configurations
Configuration 1 (hide)
|
History
07 Jul 2026, 14:52
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 4.8 |
| CPE | cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:* cpe:2.3:a:erlang:erlang\/ssl:*:*:*:*:*:*:*:* |
|
| References | () https://cna.erlef.org/cves/CVE-2026-54887.html - Vendor Advisory | |
| References | () https://github.com/erlang/otp/commit/888e3bcd72d5406016b9e0de741026bc2a6f114d - Patch | |
| References | () https://github.com/erlang/otp/security/advisories/GHSA-p2m2-3c2w-8jp8 - Vendor Advisory | |
| References | () https://osv.dev/vulnerability/EEF-CVE-2026-54887 - Third Party Advisory | |
| References | () https://www.erlang.org/doc/system/versions.html#order-of-versions - Release Notes | |
| First Time |
Erlang erlang\/ssl
Erlang erlang\/otp Erlang |
02 Jul 2026, 17:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-02 17:17
Updated : 2026-07-07 14:52
NVD link : CVE-2026-54887
Mitre link : CVE-2026-54887
CVE.ORG link : CVE-2026-54887
JSON object : View
Products Affected
erlang
- erlang\/ssl
- erlang\/otp
CWE
CWE-1394
Use of Default Cryptographic Key