How severe is CVE-2015-3257?

CVE-2015-3257 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-2015-3257?

CVE-2015-3257 affects the following packages: zendframework/zend-diactoros (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2015-3257?

Update zendframework/zend-diactoros to 1.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-3257 is resolved across your whole dependency graph.

How do I detect CVE-2015-3257 in my Packagist dependencies?

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

How do I mitigate CVE-2015-3257 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-2015-3257 actively exploited in the wild?

No public exploit code has been indexed for CVE-2015-3257 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-2015-3257?

CVE-2015-3257 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 60th 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-2015-3257?

CVE-2015-3257 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-2015-3257 published, and has it been updated?

CVE-2015-3257 was published on May 17, 2022 and was last updated on April 23, 2024. 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-2015-3257 — zend-diactoros

MEDIUM

CVE-2015-3257 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in zendframework/zend-diactoros. A fix is available for zendframework/zend-diactoros — see the affected versions and patch details below.

zend-diactoros Cross-site Scripting (XSS)

Published

May 17, 2022

Updated

Apr 23, 2024

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 ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs60th percentile — riskier than 60% 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

🐘zendframework/zend-diactoros

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

Zend/Diactoros/Uri::filterPath in zend-diactoros before 1.0.4 does not properly sanitize path input, which allows remote attackers to perform cross-site scripting (XSS) or open redirect attacks.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`zendframework/zend-diactoros`	≥ 1.0.0&&< 1.0.4	1.0.4`composer require zendframework/zend-diactoros:^1.0.4`

Affected Products

1 product · 1 configurations

Application

diactoroszend

≤ 1.0.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zendframework/zend-diactoros, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zendframework/zend-diactoros to 1.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-3257 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

`Zend/Diactoros/Uri::filterPath` in zend-diactoros before 1.0.4 does not properly sanitize path input, which allows remote attackers to perform cross-site scripting (XSS) or open redirect attacks.

O3 Security · Impact-Aware SCA

Is CVE-2015-3257 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:3.0/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

security-advisories

4.8/10

Maintained10/10

Code-Review10/10

Branch-Protection0/10

Assessed Nov 2, 2026

Timeline

Disclosed

May 17, 2022

Last updated

Apr 23, 2024

Identifiers

CVE-2015-3257

References

Advisorynvd.nist.gov · CVE 2015 3257 Webframework.zend.com · ZF2015 05 Webgithub.com · CVE 2015 3257.yaml Websecurityfocus.com Packagegithub.com · zend diactoros

Related vulnerabilities

Also affects zendframework/zend-diactoros

This CVE is medium severity; 2 of 2 other CVEs affecting zendframework/zend-diactoros are rated as high or higher (top: high).

GHSA-fq4p-86hh-42v9GHSA-f6p5-76fp-m248

Same weakness: CWE-79

This CVE is medium severity; 6 of 6 other CVEs with CWE-79 are rated as high or higher (top: critical).

CVE-2026-55649CVE-2026-113787CVE-2026-44267CVE-2026-96632CVE-2026-9086CVE-2026-118246Browse all CWE-79

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedApr 23, 2024