XSS in Simple Ajax Chat

CVE-2026-81807

The Simple Ajax Chat WordPress plugin before 20260827 does not escape chat message content before rendering it, allowing unauthenticated users to inject arbitrary HTML attributes into the page and run scripts in the browser of anyone viewing the chat, including administrators.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (41.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-81807: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

  • Simple Ajax Chat

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-81807?
CVE-2026-81807 is a high-severity vulnerability in Simple Ajax Chat, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2026-09-02.
How severe is CVE-2026-81807?
High severity. CVSS v3 base score is 8.8 out of 10.