CVE-2021-30126: Lightmeter ControlCenter 1.1.0 through 1.5.x before 1.5.1 allows anyone who knows the URL of a publicly availa

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MEDIUM 6.5REMOTEUPGRADE

CVE-2021-30126 is a medium-severity flaw (CVSS 6.5) affecting controlcenter. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Lightmeter ControlCenter 1.1.0 through 1.5.x before 1.5.1 allows anyone who knows the URL of a publicly available Lightmeter instance to access application settings, possibly including an SMTP password and a Slack access token, via a settings HTTP query.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Published	2021-04-02
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: lightmeter

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

Am I affected?

Timeline

2021-04-02 20:15 UTCPublished CVE record published
2026-06-17 03:49 UTCUpdated Record last modified

lightmeter controlcenter UPGRADE

Affected: >= 1.1.0 and < 1.5.1

Fixed in: 1.5.1

Safe to downgrade to: a release before 1.1.0

1. Check installed version

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

2. UPGRADE to 1.5.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade controlcenter

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 1.1.0 (Debian / Ubuntu)

apt-cache madison controlcenter sudo apt install controlcenter=<VERSION_BEFORE_1.1.0> sudo apt-mark hold controlcenter

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

dnf --showduplicates list controlcenter sudo dnf downgrade controlcenter-<VERSION_BEFORE_1.1.0> sudo dnf versionlock add controlcenter

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-2021-30126?

controlcenter: upgrade to 1.5.1. Exact commands for each OS are on this page.

Is CVE-2021-30126 being exploited?

CVE-2021-30126 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-2021-30126 affect?

CVE-2021-30126 affects controlcenter. Severity is medium (CVSS 6.5). Lightmeter ControlCenter 1.1.0 through 1.5.x before 1.5.1 allows anyone who knows the URL of a publicly available Lightmeter instance to access application settings, possibly including an SMTP password and a Slack access token, via a settin

How urgent is CVE-2021-30126?

Priority 41/100. Remotely exploitable, no login, no user action

Software pages

Slack vulnerabilities

References

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