CVE-2025-8261: A weakness has been identified in Vaelsys VaelsysV4 4.1.0

This week

HIGH 7.3REMOTEDOWNGRADE

CVE-2025-8261 is a high-severity flaw (CVSS 7.3) affecting vaelsys. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A weakness has been identified in Vaelsys VaelsysV4 4.1.0. This vulnerability affects unknown code of the file /grid/vgrid_server.php of the component User Creation Handler. Executing a manipulation can lead to improper authorization. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The real existence of this vulnerability is still doubted at the moment. The vendor explains:

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-266, CWE-285
Published	2025-07-28
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: vaelsys

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

Am I affected?

Timeline

2025-07-28 07:15 UTCPublished CVE record published
2026-06-17 10:06 UTCUpdated Record last modified

vaelsys vaelsys DOWNGRADE

Affected: 4.1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.1.0 (Debian / Ubuntu)

apt-cache madison vaelsys sudo apt install vaelsys=<VERSION_BEFORE_4.1.0> sudo apt-mark hold vaelsys

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list vaelsys sudo dnf downgrade vaelsys-<VERSION_BEFORE_4.1.0> sudo dnf versionlock add vaelsys

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-2025-8261?

vaelsys: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-8261 being exploited?

CVE-2025-8261 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-2025-8261 affect?

CVE-2025-8261 affects vaelsys. Severity is high (CVSS 7.3). A weakness has been identified in Vaelsys VaelsysV4 4.1.0. This vulnerability affects unknown code of the file /grid/vgrid_server.php of the component User Creation Handler. Executing a manipulation can lead to improper authorization. The a

How urgent is CVE-2025-8261?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

Related CVEs

CVE-2026-2952 HIGH 7.3 DOWNGRADE A flaw has been found in Vaelsys 4.1.0
CVE-2025-8260 LOW 3.1 DOWNGRADE A security flaw has been discovered in Vaelsys VaelsysV4 up to 5.1.0/5.4.0
CVE-2025-8259 HIGH 7.3 DOWNGRADE A vulnerability was identified in Vaelsys VaelsysV4 up to 5.1.0/5.4.0

References

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