Medium severity · published May 14, 2026
CVE-2026-6478
PostgreSQL discloses MD5-hashed passwords via covert timing channel
6.5
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PO
PostgreSQL · PostgreSQL
18 before 18.4; 17 before 17.10; 16 before 16.14; 15 before 15.18; before 14.23 · source: vendor, NVD
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 7 Extended Lifecycle Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.8 Telecommunications Update Service · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6478
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-6478
Patch
https://www.postgresql.org/support/security/CVE-2026-6478/
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:21182
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22878
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26181
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26203
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:26204
More from PostgreSQL
9.8
CVE-2015-0244
PostgreSQL before 9.0.19, 9.1.x before 9.1.15, 9.2.x before 9.2.10, 9.3.x before 9.3.6, and 9.4.x before 9.4.1 does not properly handle errors while reading a protocol message,…
9.8
CVE-2015-3166
The snprintf implementation in PostgreSQL before 9.0.20, 9.1.x before 9.1.16, 9.2.x before 9.2.11, 9.3.x before 9.3.7, and 9.4.x before 9.4.2 does not properly handle system-call…
9.8
CVE-2019-10211
Postgresql Windows installer before versions 11.5, 10.10, 9.6.15, 9.5.19, 9.4.24 is vulnerable via bundled OpenSSL executing code from unprotected directory
9.8
CVE-2018-16850
postgresql before versions 11.1, 10.6 is vulnerable to a to SQL injection in pg_upgrade and pg_dump via CREATE TRIGGER
9.8
CVE-2017-7546
PostgreSQL versions before 9.2.22, 9.3.18, 9.4.13, 9.5.8 and 9.6.4 are vulnerable to incorrect authentication flaw allowing remote attackers to gain access to database accounts…