How severe is CVE-2019-15539?

CVE-2019-15539 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-2019-15539?

CVE-2019-15539 affects the following packages: mantisbt/mantisbt (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2019-15539?

Update mantisbt/mantisbt to 2.21.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-15539 is resolved across your whole dependency graph.

How do I detect CVE-2019-15539 in my Packagist dependencies?

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

How do I mitigate CVE-2019-15539 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-2019-15539 actively exploited in the wild?

No public exploit code has been indexed for CVE-2019-15539 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-2019-15539?

CVE-2019-15539 has an EPSS (Exploit Prediction Scoring System) score of 1.2%, placing it in the 67th 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-2019-15539?

CVE-2019-15539 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-2019-15539 published, and has it been updated?

CVE-2019-15539 was published on March 19, 2020 and was last updated on October 20, 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-2019-15539 — mantisbt

MEDIUMFix: mantisbt/mantisbt@bd094de

CVE-2019-15539 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in mantisbt/mantisbt. A fix is available for mantisbt/mantisbt — see the affected versions and patch details below.

MantisBT XSS when uploading an attachment

Also known asGHSA-p495-jrpq-p66g

Published

Mar 19, 2020

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs67th percentile — riskier than 67% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐘mantisbt/mantisbt

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

The proj_doc_edit_page.php Project Documentation feature in MantisBT before 2.21.3 has a stored cross-site scripting (XSS) vulnerability, allowing execution of arbitrary code (if CSP settings permit it) after uploading an attachment with a crafted filename. The code is executed when editing the document's page.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`mantisbt/mantisbt`	all versions	2.21.3`composer require mantisbt/mantisbt:^2.21.3`

Affected Products

1 product · 1 configurations

Application

mantisbtmantisbt

< 2.21.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mantisbt/mantisbt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mantisbt/mantisbt to 2.21.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-15539 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

O3 Security · Impact-Aware SCA

Is CVE-2019-15539 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 Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

mantisbt

4.8/10

Code-Review0/10

Maintained10/10

Branch-ProtectionN/A

Assessed Nov 2, 2026

Timeline

Disclosed

Mar 19, 2020

Last updated

Oct 20, 2026

Identifiers

CVE-2019-15539

GHSA-p495-jrpq-p66g

References

Advisorynvd.nist.gov · CVE 2019 15539 Fixgithub.com · bd094dede74ff6e313e286e949e2387233a96eea Reportmantisbt.org · view Packagegithub.com · mantisbt

Related vulnerabilities

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

CVE-2026-52882CVE-2026-52883CVE-2026-52847CVE-2026-47156CVE-2026-62944CVE-2026-49280CVE-2026-47142CVE-2026-49273

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 20, 2026