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VulnerabilityPublished Updated

CVE-2026-54887: Erlang OTP · Use of Default Cryptographic Key

Affects Erlang OTPSource CVE Database V5

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 888e3bcd72d5406016b9e0de741026bc2a6f114d when convenient.

Data as of 14 Nov 2026, 20:58 UTC

CVSS 4.0 base score
6.3Medium
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (EEF)CVSS 4.06.3
EPSS
0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 888e3bcd72d5406016b9e0de741026bc2a6f114d, 11.2.12.10
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 2 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 14 Nov 2026.

What to do

Upgrade OTP to 888e3bcd72d5406016b9e0de741026bc2a6f114d; ssl to 11.2.12.10.

Affected software

ProductAffectedFixed in
OTPotpAffected
  • >=20.0 <27.3.4.14
Fixed in–
OTPsslAffected
  • >=8.2 <11.2.12.10
Fixed in–
OTPerlang/otpAffected
  • ≥ e594aad2f87aab39e99fccf9e021bc94e0bbf7d4, < 888e3bcd72d5406016b9e0de741026bc2a6f114d
Fixed in
  • 888e3bcd72d5406016b9e0de741026bc2a6f114d
GitHubsslpkg:github/sslOther threatsAffected
  • >=8.2 <11.2.12.10
Fixed in
  • 11.2.12.10

CPE configurations (1)

  • cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, administrators should be aware of the startup window risk and consider mitigating exposure during server restarts if possible.

Description

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 OTP 27.3.4.14, OTP 28.5.0.3, and OTP 29.0.3, corresponding to ssl from 8.2 before 11.2.12.10, 11.6.0.3, and 11.7.3.

References

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