CVE-2026-6478

Covert timing channel in comparison of MD5-hashed password in PostgreSQL authentication allows an attacker to recover user credentials sufficient to authenticate. This does not affect scram-sha-256 passwords, the default in all supported releases. However, current databases may have MD5-hashed passwords originating in upgrades from PostgreSQL 13 or earlier. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

What this means for your business

It affects Postgresql. It matters if your company, or a supplier that handles your data, runs it.
An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
FIRST's prediction model gives it a 0.6% chance of attack attempts being seen in the next 30 days, ranking above 45% of all known flaws.

What to do

1Check whether your company or your suppliers run Postgresql, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Fastnexa security experts

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Scoring

CVSS: 6.5 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-385
Assigned by: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007

Dates

Published: 2026-05-14
Last modified: 2026-08-25
Sources: NVD

Affected products

Postgresql Postgresql- 14.23, 15.0 - 15.18, 16.0 - 16.14, 17.0 - 17.10, 18.0 - 18.4

As listed in the NVD configuration data. Not a statement about your estate.