CVE-2021-3515: A shell injection flaw was found in pglogical in versions before 2.3.4 and before 3.6.26

Routine

MEDIUM 6.7UPGRADE

CVE-2021-3515 is a medium-severity flaw (CVSS 6.7) affecting pglogical. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A shell injection flaw was found in pglogical in versions before 2.3.4 and before 3.6.26. An attacker with CREATEDB privileges on a PostgreSQL server can craft a database name that allows execution of shell commands as the postgresql user when calling pglogical.create_subscription().

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.7 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-77, CWE-78
Published	2021-06-01
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: 2ndquadrant

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

Am I affected?

Timeline

2021-06-01 14:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

2ndquadrant pglogical UPGRADE

Affected: < 2.3.4 · >= 3.0.0 and < 3.6.26

Fixed in: 2.3.4, 3.6.26

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. UPGRADE to 2.3.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pglogical

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 3.0.0 (Debian / Ubuntu)

apt-cache madison pglogical sudo apt install pglogical=<VERSION_BEFORE_3.0.0> sudo apt-mark hold pglogical

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

dnf --showduplicates list pglogical sudo dnf downgrade pglogical-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add pglogical

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-2021-3515?

pglogical: upgrade to 2.3.4, 3.6.26. Exact commands for each OS are on this page.

Is CVE-2021-3515 being exploited?

CVE-2021-3515 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-2021-3515 affect?

CVE-2021-3515 affects pglogical. Severity is medium (CVSS 6.7). A shell injection flaw was found in pglogical in versions before 2.3.4 and before 3.6.26. An attacker with CREATEDB privileges on a PostgreSQL server can craft a database name that allows execution of shell commands as the postgresql user w

How urgent is CVE-2021-3515?

Priority 33/100. No elevated risk signals yet.

Software pages

PostgreSQL vulnerabilities

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References

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