CVE-2026-6478

🔶 medium

Summary

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 Score

6.5

Medium

EPSS Score

0.1

Exploit Probability

Published Date

2026-05-14

First Seen: 2026-05-17

📊 Relative Risk Intelligence

This CVE is Lower Risk - more severe than 47.8% of all 328,009 vulnerabilities in our database.

#171,192

Below average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: May 14, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

YES

Can be exploited automatically

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

The PostgreSQL project thanks Joe Conway for reporting this problem.

SSVC data provided by CISA

Last Modified 2026-05-18

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CWE IDs (Weakness Types)

CWE-385

📦 Affected Products 5

Vendor	Product	Status	Affected Versions
postgresql	postgresql	Affected	< 14.23
postgresql	postgresql	Affected	> 15.0 < 15.18
postgresql	postgresql	Affected	> 16.0 < 16.14
postgresql	postgresql	Affected	> 17.0 < 17.10
postgresql	postgresql	Affected	> 18.0 < 18.4

🔗 References 1

https://www.postgresql.org/support/security/CVE-2026...

Patch Vendor Advisory

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-6472	🔶 medium	5.4	0.0	Missing authorization in PostgreSQL CREATE TYPE allows an object creator to hijack other queries that use search_path to...	2026-05-14
CVE-2026-6473	⚠️ high	8.8	0.1	Integer wraparound in multiple PostgreSQL server features allows an unprivileged database user to cause the server to un...	2026-05-14
CVE-2026-6474	🔶 medium	4.3	0.0	Externally-controlled format string in PostgreSQL timeofday() function allows an attacker to retrieve portions of server...	2026-05-14
CVE-2026-6475	⚠️ high	8.8	0.1	Symlink following in PostgreSQL pg_basebackup plain format and in pg_rewind allows an origin superuser to overwrite loca...	2026-05-14
CVE-2026-6476	⚠️ high	7.2	0.0	SQL injection in PostgreSQL pg_createsubscriber allows an attacker with pg_create_subscription rights to execute arbitra...	2026-05-14
CVE-2026-6477	⚠️ high	8.8	0.1	Use of inherently dangerous function PQfn(..., result_is_int=0, ...) in PostgreSQL libpq lo_export(), lo_read(), lo_lsee...	2026-05-14

These CVEs affect the same products