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 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 29.0.2 corresponding to ssh from 6.0 before 6.0.1.
References
| Link | Resource |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-48859.html | Mitigation Third Party Advisory |
| https://github.com/erlang/otp/commit/c342092ef4b369bb409d5b71ac8fd83bab74aedf | Patch |
| https://github.com/erlang/otp/security/advisories/GHSA-3w6p-vwhf-wvp4 | Mitigation Vendor Advisory |
| https://osv.dev/vulnerability/EEF-CVE-2026-48859 | Mitigation Third Party Advisory |
| https://www.erlang.org/doc/system/versions.html#order-of-versions | Product |
Configurations
Configuration 1 (hide)
|
History
15 Jun 2026, 18:23
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Erlang erlang\/ssh
Erlang Erlang erlang\/otp |
|
| CPE | cpe:2.3:a:erlang:erlang\/ssh:*:*:*:*:*:*:*:* cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.3 |
| References | () https://cna.erlef.org/cves/CVE-2026-48859.html - Mitigation, Third Party Advisory | |
| References | () https://github.com/erlang/otp/commit/c342092ef4b369bb409d5b71ac8fd83bab74aedf - Patch | |
| References | () https://github.com/erlang/otp/security/advisories/GHSA-3w6p-vwhf-wvp4 - Mitigation, Vendor Advisory | |
| References | () https://osv.dev/vulnerability/EEF-CVE-2026-48859 - Mitigation, Third Party Advisory | |
| References | () https://www.erlang.org/doc/system/versions.html#order-of-versions - Product |
10 Jun 2026, 16:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-06-10 16:17
Updated : 2026-06-15 18:23
NVD link : CVE-2026-48859
Mitre link : CVE-2026-48859
CVE.ORG link : CVE-2026-48859
JSON object : View
Products Affected
erlang
- erlang\/ssh
- erlang\/otp
CWE
CWE-208
Observable Timing Discrepancy