How severe is CVE-2017-7271?

CVE-2017-7271 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-2017-7271?

CVE-2017-7271 affects the following packages: yiisoft/yii2 (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2017-7271?

Update yiisoft/yii2 to 2.0.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-7271 is resolved across your whole dependency graph.

How do I detect CVE-2017-7271 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yiisoft/yii2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2017-7271 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-2017-7271 actively exploited in the wild?

No public exploit code has been indexed for CVE-2017-7271 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-2017-7271?

CVE-2017-7271 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 64th 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-2017-7271?

CVE-2017-7271 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-2017-7271 published, and has it been updated?

CVE-2017-7271 was published on March 27, 2017 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-2017-7271 — yii2

MEDIUMFix: yiisoft/yii2@97171a0

CVE-2017-7271 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in yiisoft/yii2. A fix is available for yiisoft/yii2 — see the affected versions and patch details below.

Yii Framework Reflected XSS

Also known asGHSA-4xh9-5vh8-3p58

Published

Mar 27, 2017

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs64th percentile — riskier than 64% 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

🐘yiisoft/yii2

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

Reflected Cross-site scripting (XSS) vulnerability in Yii Framework before 2.0.11, when development mode is used, allows remote attackers to inject arbitrary web script or HTML via crafted request data that is mishandled on the debug-mode exception screen.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`yiisoft/yii2`	all versions	2.0.11`composer require yiisoft/yii2:^2.0.11`

Affected Products

1 product · 1 configurations

Application

yiiyii_software

≤ 2.0.10

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yiisoft/yii2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update yiisoft/yii2 to 2.0.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-7271 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-2017-7271 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

yii2

7.3/10

Dependency-Update-Tool10/10

Code-Review10/10

Maintained10/10

Vulnerabilities10/10

Branch-Protection3/10

Assessed Nov 4, 2026

Timeline

Disclosed

Mar 27, 2017

Last updated

Oct 20, 2026

Identifiers

CVE-2017-7271

GHSA-4xh9-5vh8-3p58

References

Advisoryyiiframework.com · yii 2 0 11 is released Advisorynvd.nist.gov · CVE 2017 7271 Fixgithub.com · 97171a0db7cda0a49931ee0c3b998ef50bd06756 Fixgithub.com Websecurityfocus.com Webweb.archive.org Webyiiframework.com · yii 2 0 11 is released Packagegithub.com · yii2

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting yiisoft/yii2 are rated as high or higher (top: critical).

CVE-2026-39850CVE-2024-58136CVE-2024-4990CVE-2024-32877CVE-2015-5467CVE-2017-11516CVE-2015-3397CVE-2018-20745

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 20, 2026