CVE-2026-29964

MEDIUM

HSC MailInspector 5.3.3-7 - Cross-Site Scripting via /tap/tap.php Endpoint

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-29964. PoCs published by sql3t0.

AI-analyzed exploit summary This repository contains a detailed security advisory for CVE-2026-29964, describing an XSS vulnerability in MailInspector v5.3.3-7 due to improper neutralization of alternate script syntax in the `/mailinspector/tap/tap.php` endpoint. The advisory includes impact analysis, affected versions, and CVSS scoring.

Description

HSC MailInspector v5.3.3-7 contains a Cross-Site Scripting (XSS) vulnerability in the /tap/tap.php endpoint due to improper neutralization of user-controlled input using alternate or obfuscated JavaScript syntax. The endpoint reflects unsanitized user input in HTTP responses without adequate output encoding, allowing a remote attacker to execute arbitrary JavaScript code in the context of a victim's browser.

Exploits (1)

github WRITEUP
by sql3t0 · poc
https://github.com/sql3t0/cve-disclosures/tree/main/03_-_CVE-2026-29964_XSS.md

This repository contains a detailed security advisory for CVE-2026-29964, describing an XSS vulnerability in MailInspector v5.3.3-7 due to improper neutralization of alternate script syntax in the `/mailinspector/tap/tap.php` endpoint. The advisory includes impact analysis, affected versions, and CVSS scoring.

Classification
Writeup 90%
Attack Type
Xss
Complexity
Trivial
Reliability
Theoretical
Target: MailInspector v5.3.3-7
No auth needed
Prerequisites: Access to the vulnerable endpoint `/mailinspector/tap/tap.php`
devstral-2 · analyzed May 18, 2026 Full analysis →

References (3)

Core 3

Scores

CVSS v3 6.1
EPSS 0.0004
EPSS Percentile 13.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (1)
hsclabs/mailinspector 5.3.3-7
Published May 18, 2026
Tracked Since May 18, 2026