VulnerabilityModified

CVE-2017-18343

MEDIUM 6.1EPSS 6.11%

Does this matter?

Lower severity and a low EPSS score (6.11%). Track it; it rarely justifies an emergency change on its own.

Description

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

CVSS 3.0: 6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS: 6.11% probability · 93th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-79
Affected: sensiolabs/symfony
Source: cve@mitre.org

EPSS trend

EPSS moved from 14.2% on 21 September 2026 to 6.1% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.

References

https://github.com/barryvdh/laravel-debugbar/issues/850Exploit, Third Party Advisory
https://github.com/symfony/debug/pull/7/commits/e48bda29143bd1a83001780b4a78e483822d985cPatch, Third Party Advisory
https://github.com/symfony/symfony/issues/27987Exploit, Third Party Advisory
https://github.com/symfony/symfony/pull/23684Third Party Advisory
https://github.com/barryvdh/laravel-debugbar/issues/850Exploit, Third Party Advisory
https://github.com/symfony/debug/pull/7/commits/e48bda29143bd1a83001780b4a78e483822d985cPatch, Third Party Advisory
https://github.com/symfony/symfony/issues/27987Exploit, Third Party Advisory
https://github.com/symfony/symfony/pull/23684Third Party Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.