CVE-2026-40342: Firebird is an open-source relational database management system

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CRITICAL 9.9UPGRADE

CVE-2026-40342 is a critical-severity flaw (CVSS 9.9) affecting firebird. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, the external engine plugin loader concatenates a user-supplied engine name into a filesystem path without filtering path separators or .. components. An authenticated user with CREATE FUNCTION privileges can use a crafted ENGINE name to load an arbitrary shared library from anywhere on the filesystem via path traversal. The library's in

Why this priority

Critical severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.9 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-22, CWE-73, CWE-94, CWE-427
Published	2026-04-17
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: firebirdsql

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-17 20:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

firebirdsql firebird UPGRADE

Affected: < 3.0.14 · >= 4.0.0 and < 4.0.7 · >= 5.0.0 and < 5.0.4

Fixed in: 3.0.14, 4.0.7, 5.0.4

Safe to downgrade to: a release before 4.0.0

1. Check installed version

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

2. UPGRADE to 3.0.14 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade firebird

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 4.0.0 (Debian / Ubuntu)

apt-cache madison firebird sudo apt install firebird=<VERSION_BEFORE_4.0.0> sudo apt-mark hold firebird

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

dnf --showduplicates list firebird sudo dnf downgrade firebird-<VERSION_BEFORE_4.0.0> sudo dnf versionlock add firebird

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-2026-40342?

firebird: upgrade to 3.0.14, 4.0.7, 5.0.4. Exact commands for each OS are on this page.

Is CVE-2026-40342 being exploited?

CVE-2026-40342 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-2026-40342 affect?

CVE-2026-40342 affects firebird. Severity is critical (CVSS 9.9). Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, the external engine plugin loader concatenates a user-supplied engine name into a filesystem path without filtering path separat

How urgent is CVE-2026-40342?

Priority 53/100. Critical severity; Public exploit reference

Related CVEs

CVE-2026-35215 HIGH 7.5 UPGRADE Firebird is an open-source relational database management system
CVE-2026-27890 HIGH 8.2 UPGRADE Firebird is an open-source relational database management system
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CVE-2026-33337 HIGH 7.5 UPGRADE Firebird is an open-source relational database management system
CVE-2026-28212 HIGH 7.5 UPGRADE Firebird is an open-source relational database management system

References

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