A Cross Site Scripting (XSS) issue exists in Avast AntiVirus (Free, Internet Security, and Premiere Edition) 19.3.2369 build 19.3.4241.440…

published 2019-11-01 7y ago modified 2026-06-17 4mo ago also EUVD-2019-8372

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits: 0; none known

A Cross Site Scripting (XSS) issue exists in Avast AntiVirus (Free, Internet Security, and Premiere Edition) 19.3.2369 build 19.3.4241.440 in the Network Notification Popup, allowing an attacker to execute JavaScript code via an SSID Name.

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Exploit prediction

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

firstsight.me http://firstsight.me/2019/10/5000-usd-xss-issue-at-avast-desktop-antivirus-for-windows-yes-desktop/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

CVE List CVE-2019-18653
NVD CVE-2019-18653

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.