Answer in brief
CVE-2026-121863 records a Unknown severity vulnerability in Knowledge Building < 0.7.3 - Reflected XSS via Comment Reply Response. The current sources do not mark it as known exploited. The current feed maps Unknown/Knowledge Building (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Unknown/Knowledge Building (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Unknown/Knowledge Buildinggeneric | >=0 <0.7.3 | 0.7.3 |
Published upstream
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 11, 2026
The Knowledge Building WordPress plugin before 0.7.3 does not escape several user-supplied values before echoing them back in the response of an AJAX action available to unauthenticated users, and serves that response as HTML, leading to a Reflected Cross-Site Scripting.
Quoted source text, attributed separately from HOL analysis.