CVE search · CVE-2026-48859
CVE-2026-48859
medium 6.3
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.
Details
- Status
- Modified
- Published
- Last changed
- Source
- 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
- Weakness
- CWE-208
Severity
| Version | Score | Vector | Source |
|---|---|---|---|
| CVSS 4.0 | medium 6.3 | 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/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 |
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbSecondary |
| CVSS 3.1 | medium 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
nvd@nist.govPrimary |
Affected products
Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.
References
- https://cna.erlef.org/cves/CVE-2026-48859.htmlMitigationThird Party Advisory
- https://github.com/erlang/otp/commit/c342092ef4b369bb409d5b71ac8fd83bab74aedfPatch
- https://github.com/erlang/otp/security/advisories/GHSA-3w6p-vwhf-wvp4MitigationVendor Advisory
- https://osv.dev/vulnerability/EEF-CVE-2026-48859MitigationThird Party Advisory
- https://www.erlang.org/doc/system/versions.html#order-of-versionsProduct