PostgreSQL discloses MD5-hashed passwords via covert timing channel
Summary
| CVE | CVE-2026-6478 |
|---|---|
| State | PUBLISHED |
| Assigner | PostgreSQL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-14 14:16:25 UTC |
| Updated | 2026-05-18 15:03:55 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS: 0.000760000 probability, percentile 0.226540000 (date 2026-05-25)
Problem Types: CWE-385 | CWE-385 Covert Timing Channel
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
| 3.1 | CNA | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Postgresql | Postgresql | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Na | PostgreSQL | affected 18 18.4 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 17 17.10 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 16 16.14 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 15 15.18 rpm | Not specified |
| CNA | Na | PostgreSQL | affected 14.23 rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.postgresql.org/support/security/CVE-2026-6478 | f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 | www.postgresql.org | Patch, Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: The PostgreSQL project thanks Joe Conway for reporting this problem. (en)
Additional Advisory Data
Workarounds
CNA: reset password with password_encryption=scram-sha-256
There are currently no legacy QID mappings associated with this CVE.