CVE-2017-18343

What it is

The debug handler in Symfony before v2.7.33, 2.8.x before v2.8.26, 3.x before v3.2.13, and 3.3.x before v3.3.6 has XSS via an array key during exception pretty printing in ExceptionHandler.php, as demonstrated by a /_debugbar/open?op=get URI. NOTE: the vendor's position is that this is not a vulnerability because the debug tools are not intended for production use. NOTE: the Symfony Debug component is used by Laravel Debugbar

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.

Exploit odds

6.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2018-07-20 00:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 01:12 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 6.1% in the next 30 days (EPSS).
• Severity: 6.1 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2018-07-20 00:29 UTC

Last modified

2026-06-17 01:12 UTC

Exploit probability

6.1% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Modified

Affected

• Sensiolabs Symfony < 2.7.33
• Sensiolabs Symfony < 2.8.26
• Sensiolabs Symfony < 3.2.13
• Sensiolabs Symfony < 3.3.6

Attack profile CVSS 3.0 · 6.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2017-18343.md and follow it. Check whether this project is affected by CVE-2017-18343. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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