How severe is CVE-2020-15721?

CVE-2020-15721 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-15721?

CVE-2020-15721 affects the following packages: francoisjacquet/rosariosis (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2020-15721?

Update francoisjacquet/rosariosis to 6.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15721 is resolved across your whole dependency graph.

How do I detect CVE-2020-15721 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for francoisjacquet/rosariosis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-15721 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2020-15721 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-15721 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2020-15721?

CVE-2020-15721 has an EPSS (Exploit Prediction Scoring System) score of 1.5%, placing it in the 73th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2020-15721?

CVE-2020-15721 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2020-15721 published, and has it been updated?

CVE-2020-15721 was published on July 14, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

MEDIUM severity

CVE-2020-15721 — rosariosis

MEDIUM

CVE-2020-15721 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in francoisjacquet/rosariosis. A fix is available for francoisjacquet/rosariosis — see the affected versions and patch details below.

Cross-site Scripting in RosarioSIS

Also known asGHSA-6vc5-v7hw-h5h2

Published

Jul 14, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs73th percentile — riskier than 73% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-15721 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐘francoisjacquet/rosariosis

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

RosarioSIS through 6.8-beta allows modules/Custom/NotifyParents.php XSS because of the href attributes for AddStudents.php and User.php.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`francoisjacquet/rosariosis`	all versions	6.8`composer require francoisjacquet/rosariosis:^6.8`

Affected Products

1 product · 3 configurations

Application

rosariosisrosariosis

≤ 6.7.2

1 version

6.8

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for francoisjacquet/rosariosis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update francoisjacquet/rosariosis to 6.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15721 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

RosarioSIS through 6.8-beta allows modules/Custom/NotifyParents.php XSS because of the href attributes for AddStudents.php and User.php.

O3 Security · Impact-Aware SCA

Is CVE-2020-15721 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Jul 14, 2020

Last updated

Jul 8, 2026

Identifiers

CVE-2020-15721

GHSA-6vc5-v7hw-h5h2

References

Advisorygitlab.com Advisorynvd.nist.gov Fixgitlab.com Reportgitlab.com

Related vulnerabilities

This CVE is medium severity; 7 of 8 other CVEs affecting francoisjacquet/rosariosis are rated as high or higher (top: critical).

CVE-2024-3138CVE-2023-2665CVE-2023-29918CVE-2023-2202CVE-2023-0994CVE-2022-2714CVE-2022-3072CVE-2022-2067

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 8, 2026