CVE-2026-2742: An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-2742 is a medium-severity flaw (CVSS 5.3) affecting vaadin. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7 and 25.0.0 through 25.0.1, applications using Spring Security due to inconsistent path pattern matching of reserved framework paths. Accessing the /VAADIN endpoint without a trailing slash bypasses security filters, and allowing unauthenticated users to trigger framework initialization and create sessions without proper au

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-284
Published	2026-03-10
Last modified	2026-06-17

Publisher (CNA): Vaadin Ltd. · Vendor: vaadin

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

Am I affected?

Timeline

2026-03-10 18:18 UTCPublished CVE record published
2026-06-17 10:31 UTCUpdated Record last modified

vaadin vaadin UPGRADE

Affected: >= 10.0.0 and < 14.14.1 · >= 15.0.0 and < 23.6.7 · >= 24.0.0 and < 24.9.8 · >= 25.0.0 and < 25.0.2

Fixed in: 14.14.1, 23.6.7, 24.9.8, 25.0.2

Safe to downgrade to: a release before 10.0.0

1. Check installed version

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

2. UPGRADE to 14.14.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vaadin

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 10.0.0 (Debian / Ubuntu)

apt-cache madison vaadin sudo apt install vaadin=<VERSION_BEFORE_10.0.0> sudo apt-mark hold vaadin

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

dnf --showduplicates list vaadin sudo dnf downgrade vaadin-<VERSION_BEFORE_10.0.0> sudo dnf versionlock add vaadin

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-2026-2742?

vaadin: upgrade to 14.14.1, 23.6.7, 24.9.8, 25.0.2. Exact commands for each OS are on this page.

Is CVE-2026-2742 being exploited?

CVE-2026-2742 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-2026-2742 affect?

CVE-2026-2742 affects vaadin. Severity is medium (CVSS 5.3). An authentication bypass vulnerability exists in Vaadin 14.0.0 through 14.14.0, 23.0.0 through 23.6.6, 24.0.0 through 24.9.7 and 25.0.0 through 25.0.1, applications using Spring Security due to inconsistent path pattern matching of reserved

How urgent is CVE-2026-2742?

Priority 32/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-2741 MEDIUM 6.8 UPGRADE Specially crafted ZIP archives can escape the intended extraction directory during Node.js download and extrac

References

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