CVE-2025-50866: CloudClassroom-PHP-Project 1.0 contains a reflected Cross-site Scripting (XSS) vulnerability in the email para

Routine

MEDIUM 6.1DOWNGRADE

CVE-2025-50866 is a medium-severity flaw (CVSS 6.1) affecting cloudclassroom. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

CloudClassroom-PHP-Project 1.0 contains a reflected Cross-site Scripting (XSS) vulnerability in the email parameter of the postquerypublic endpoint. Improper sanitization allows an attacker to inject arbitrary JavaScript code that executes in the context of the user s browser, potentially leading to session hijacking or phishing attacks.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Weakness	CWE-79
Published	2025-07-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: vishalmathur

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

Am I affected?

Timeline

2025-07-31 17:15 UTCPublished CVE record published
2026-06-17 09:35 UTCUpdated Record last modified

vishalmathur cloudclassroom DOWNGRADE

Affected: 1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)

apt-cache madison cloudclassroom sudo apt install cloudclassroom=<VERSION_BEFORE_1.0> sudo apt-mark hold cloudclassroom

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

dnf --showduplicates list cloudclassroom sudo dnf downgrade cloudclassroom-<VERSION_BEFORE_1.0> sudo dnf versionlock add cloudclassroom

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-2025-50866?

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

Is CVE-2025-50866 being exploited?

CVE-2025-50866 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-2025-50866 affect?

CVE-2025-50866 affects cloudclassroom. Severity is medium (CVSS 6.1). CloudClassroom-PHP-Project 1.0 contains a reflected Cross-site Scripting (XSS) vulnerability in the email parameter of the postquerypublic endpoint. Improper sanitization allows an attacker to inject arbitrary JavaScript code that executes

How urgent is CVE-2025-50866?

Priority 27/100. No elevated risk signals yet.

Software pages

PHP vulnerabilities

Related CVEs

CVE-2025-50867 MEDIUM 6.5 DOWNGRADE A SQL Injection vulnerability exists in the takeassessment2.php endpoint of the CloudClassroom-PHP-Project 1.0

References

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