Description
YesWiki before 4.6.7 contains a stored cross-site scripting vulnerability in the Bazar FileField, which validates only the upload's file extension and never calls HtmlPurifierService::cleanFile, so SVG files are stored verbatim and served inline as image/svg+xml. Authenticated users can submit entries via POST /api/entries/{formId} with SVG files containing script that executes in the wiki origin when the file is opened, enabling administrator session or account compromise.
References3
Metrics
- CVSS 3.1
-
5.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 4.0
-
5.1
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 11 · as of 10 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.