CVE-2026-6479: Uncontrolled recursion in PostgreSQL SSL and GSS negotiation allows an attacker able to connect to a PostgreSQ

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-6479 is a high-severity flaw (CVSS 7.5) affecting postgresql. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Uncontrolled recursion in PostgreSQL SSL and GSS negotiation allows an attacker able to connect to a PostgreSQL AF_UNIX socket to achieve sustained denial of service. If SSL and GSS are both disabled, an attacker can do the same via access to a PostgreSQL TCP socket. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-05-14
Last modified	2026-06-17

Publisher (CNA): PostgreSQL · Vendor: postgresql

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-14 14:16 UTCPublished CVE record published
2026-06-17 11:00 UTCUpdated Record last modified

postgresql postgresql UPGRADE

Affected: < 14.23 · >= 15.0 and < 15.18 · >= 16.0 and < 16.14 · >= 17.0 and < 17.10 · >= 18.0 and < 18.4

Fixed in: 14.23, 15.18, 16.14, 17.10, 18.4

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy postgresql || rpm -q postgresql || postgresql --version

2. UPGRADE to 14.23 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade postgresql

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade postgresql

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison postgresql sudo apt install postgresql=<VERSION_BEFORE_15.0> sudo apt-mark hold postgresql

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list postgresql sudo dnf downgrade postgresql-<VERSION_BEFORE_15.0> sudo dnf versionlock add postgresql

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-6479?

postgresql: upgrade to 14.23, 15.18, 16.14, 17.10, 18.4. Exact commands for each OS are on this page.

Is CVE-2026-6479 being exploited?

CVE-2026-6479 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-6479 affect?

CVE-2026-6479 affects postgresql. Severity is high (CVSS 7.5). Uncontrolled recursion in PostgreSQL SSL and GSS negotiation allows an attacker able to connect to a PostgreSQL AF_UNIX socket to achieve sustained denial of service. If SSL and GSS are both disabled, an attacker can do the same via access

How urgent is CVE-2026-6479?

Priority 43/100. High severity; Remotely exploitable, no login, no user action

Software pages

PostgreSQL vulnerabilities

Related CVEs

CVE-2026-6471 HIGH 7.2 UPGRADE Missing authorization in PostgreSQL logical decoding allows a non-superuser holding REPLICATION privilege to d
CVE-2026-6470 MEDIUM 4.3 UPGRADE Missing authorization in PostgreSQL DDL commands allows an object creator to achieve denial of service against
CVE-2026-6469 LOW 3.8 UPGRADE Incorrect ownership assignment in PostgreSQL ALTER TABLE ALTER TYPE command reassigns ownership of dependent s
CVE-2026-6464 HIGH 8.1 UPGRADE Untrusted data inclusion in PostgreSQL psql COPY may allow a server administrator to elicit execution of data
CVE-2026-19385 HIGH 8.8 UPGRADE Heap buffer overflow in PostgreSQL pg_dump of long function transform lists allows an object creator to execut

References

← Back to latest CVEs