CVE-2026-48859

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Source
https://cve.org/CVERecord?id=CVE-2026-48859
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48859.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-48859
Aliases
Downstream
Published
2026-06-10T14:35:43Z
Modified
2026-09-09T03:31:02Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
SSH server timing side-channel in ssh_auth:check_password/3 allows unauthenticated username enumeration
Details

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 OTP 29.0.2, corresponding to ssh from 6.0 before 6.0.1.

Database specific 
{
    "cna_assigner": "EEF",
    "cwe_ids": [
        "CWE-208"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48859.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "6.0"
                },
                {
                    "fixed": "6.0.1"
                },
                {
                    "introduced": "032d1bc9491a3975c68faf9bc7776115d6ae3005"
                },
                {
                    "fixed": "c342092ef4b369bb409d5b71ac8fd83bab74aedf"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/erlang/otp

Affected ranges

Type
GIT
Repo
https://github.com/erlang/otp
Events
Introduced
550d7b7898706c7822362c42e7b93120c1d1f29a
Fixed
36b336d7675edfb976768465c5067bc8bc16ee9a
Fixed
c342092ef4b369bb409d5b71ac8fd83bab74aedf
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "29.0"
        },
        {
            "fixed": "29.0.2"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

OTP-29.*
OTP-29.0
OTP-29.0.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48859.json"