CVE Intelligence
Medium

CVE-2026-6478 — PostgreSQL discloses MD5-hashed passwords via covert timing channel

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.

Published May 14, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: PostgreSQL

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.6% (30-day exploitation probability)+7
  • Technical severity (medium)+3
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.56%
ahead of 45% of scored CVEs · Oct 14, 2026
Affects
Postgresql
Postgresql
CVSS base
6.5
Medium · 3 source(s)
Prioritization reference: 8.2 provisional

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Postgresql Postgresql).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Postgresql Postgresql < 14.23≥ 15.0 and < 15.18≥ 16.0 and < 16.14≥ 17.0 and < 17.10≥ 18.0 and < 18.4 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.2 CVSS 3.1 High 3.9 4.2 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium 3.9 2.5 f86ef6dc-4d3a-42ad-8f28-e6d5547a5007 via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium — — PostgreSQL via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N (score shown at the top: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.2 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-385

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.56%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 6.5
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    May 14, 2026 · PostgreSQL

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

38 on the record

Elsewhere on this site

Postgresql
every CVE for this vendor
CWE-385
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-6471 PostgreSQL logical decoding can dlopen arbitrary file Aug 13, 2026
  • CVE-2026-6464 PostgreSQL psql COPY FROM STDIN early failure processes data lines as psql commands Aug 13, 2026
  • CVE-2026-6469 PostgreSQL ALTER TABLE ALTER TYPE resets extended statistics ownership Aug 13, 2026
  • CVE-2026-6470 PostgreSQL fails to check type USAGE privilege Aug 13, 2026
  • CVE-2026-19385 PostgreSQL pg_dump heap buffer overflow executes arbitrary code Aug 13, 2026
  • CVE-2026-18408 PostgreSQL psql \unrestrict lets superuser of pg_dump origin server execute arbitrary code in psql client Aug 13, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-6478 is "PostgreSQL discloses MD5-hashed passwords via covert timing channel", rated Medium. It affects Postgresql (Postgresql); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. EPSS 0.56% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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