CVE-2026-6478
Description
A flaw was found in PostgreSQL. This vulnerability, a covert timing channel, exists in the comparison of MD5-hashed passwords during authentication. A remote attacker could exploit this to recover user credentials, gaining unauthorized access to the database. This issue specifically impacts databases that retain MD5-hashed passwords from upgrades of PostgreSQL 13 or earlier.
Mitigation
To mitigate this vulnerability, ensure that all PostgreSQL user passwords are not hashed using MD5. Users should migrate to stronger hashing algorithms such as `scram-sha-256`. This can be achieved by altering user passwords, which will automatically update their hash to the currently configured default. For example, to change a user's password: `ALTER USER username WITH PASSWORD 'new_password';` This action will require users to re-authenticate. If a service relies on these credentials, it may require a restart to pick up the new authentication details.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.2 | N/A | 8.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Understanding the Weakness (CWE)
Confidentiality,Other
Technical Impact: Read Application Data; Other
Information exposure.
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