CVE-2026-18024: Buffer over-read in PostgreSQL ascii() SQL function allows a user to disclose up to 3 bytes after the end of a

Routine

MEDIUM 4.3UPGRADE

CVE-2026-18024 is a medium-severity flaw (CVSS 4.3) affecting postgresql. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer over-read in PostgreSQL ascii() SQL function allows a user to disclose up to 3 bytes after the end of a specific allocation, via a crafted text value. This is the same class of defect that CVE-2026-2006 fixed, though this instance has less impact. Versions before PostgreSQL 18.6, 17.11, 16.15, 15.19, and 14.24 are affected.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-126
Published	2026-08-13
Last modified	2026-08-29

Publisher (CNA): PostgreSQL · Vendor: postgresql

Last updated 2026-08-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-13 13:17 UTCPublished CVE record published
2026-08-29 23:17 UTCUpdated Record last modified

postgresql postgresql UPGRADE

Affected: >= 14.0 and < 14.24 · >= 15.0 and < 15.19 · >= 16.0 and < 16.15 · >= 17.0 and < 17.11 · >= 18.0 and < 18.5

Fixed in: 14.24, 15.19, 16.15, 17.11, 18.5

Safe to downgrade to: a release before 14.0

1. Check installed version

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

2. UPGRADE to 14.24 (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 14.0 (Debian / Ubuntu)

apt-cache madison postgresql sudo apt install postgresql=<VERSION_BEFORE_14.0> 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_14.0> 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-2026-18024?

postgresql: upgrade to 14.24, 15.19, 16.15, 17.11, 18.5. Exact commands for each OS are on this page.

Is CVE-2026-18024 being exploited?

CVE-2026-18024 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-2026-18024 affect?

CVE-2026-18024 affects postgresql. Severity is medium (CVSS 4.3). Buffer over-read in PostgreSQL ascii() SQL function allows a user to disclose up to 3 bytes after the end of a specific allocation, via a crafted text value. This is the same class of defect that CVE-2026-2006 fixed, though this instance h

How urgent is CVE-2026-18024?

Priority 21/100. No elevated risk signals yet.

Software pages

PostgreSQL vulnerabilities

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References

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