Cyber Resilience

CVE-2026-48859

Erlang\/Otp 29.0 – 29.0.2

Published
10 June 2026
Modified
03 August 2026
Patch / advisory
View 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:L/VI:N/VA:N/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 0.0035 28th 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-2026-48859 is a medium-severity Observable Timing Discrepancy (CWE-208) vulnerability in Erlang Erlang\/Otp. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Password Guessing (T1110.001); ranked at the 28th 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 SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Observable Timing Discrepancy vulnerability in Erlang/OTP ssh (ssh_auth, ssh_options modules) allows unauthenticated remote username enumeration via timing side-channel in password authentication. When the SSH daemon is configured with the user_passwords or password option, ssh_auth:check_password/3 performs a PBKDF2-SHA256 computation with 600,000…

more

iterations (~300ms) for valid usernames, but returns immediately (~0ms) for invalid usernames via the ssh_options:get_password_option/2 path. This timing difference is detectable in a single authentication attempt and allows an unauthenticated attacker to distinguish valid from invalid usernames. The user_passwords and password options are documented as intended for test purposes; the recommended alternative is pwdfun, which is not affected by this vulnerability. This vulnerability is associated with program files lib/ssh/src/ssh_auth.erl and lib/ssh/src/ssh_options.erl. This issue affects OTP from OTP 29.0 before OTP 29.0.2, corresponding to ssh from 6.0 before 6.0.1.

CWE(s)
CWE-208

Related Threats

MITRE ATT&CK Enterprise Techniques

T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
attack.mitre.org →
T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
attack.mitre.org →
T1087.001 Local Account Discovery
Adversaries may attempt to get a listing of local system accounts.
attack.mitre.org →
T1087.002 Domain Account Discovery
Adversaries may attempt to get a listing of domain accounts.
attack.mitre.org →
T1087.003 Email Account Discovery
Adversaries may attempt to get a listing of email addresses and accounts.
attack.mitre.org →
T1087.004 Cloud Account Discovery
Adversaries may attempt to get a listing of cloud accounts.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-53422Same product: Erlang Erlang\/Otp
CVE-2026-48855Same product: Erlang Erlang\/Otp
CVE-2026-23942Same product: Erlang Erlang\/Otp
CVE-2026-32147Same product: Erlang Erlang\/Otp
CVE-2026-23943Same product: Erlang Erlang\/Otp
CVE-2026-54886Same product: Erlang Erlang\/Otp
CVE-2026-28810Same product: Erlang Erlang\/Otp
CVE-2026-42790Same product: Erlang Erlang\/Otp
CVE-2026-42791Same product: Erlang Erlang\/Otp
CVE-2026-42789Same product: Erlang Erlang\/Otp

Affected Assets

erlang
erlang\/otp
29.0 — 29.0.2
erlang
erlang\/ssh
6.0 — 6.0.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V11.2.4

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing can include timing analysis or side-channel test cases that reveal observable timing discrepancies.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can mandate constant-time algorithms and side-channel resistance so timing discrepancies are never introduced.

SC-13 Cryptographic Protection partial match

Requiring approved cryptographic modules and algorithms implicitly demands implementations free of observable timing leaks.

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-06 mostly match
prevents

Secure SDLC practices directly require constant-time implementations that eliminate observable timing discrepancies.

References