CVE-2026-29964

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.

CVSS v3.1 Score

6.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0004

Probability of exploitation

0.13%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
hsclabs	mailinspector	All

References

Other References

https://github.com/sql3t0/cve-disclosures https://github.com/sql3t0/cve-disclosures/blob/main/03_-_CVE-2026-29964_XSS.md https://hsclabs.com/pt-br/mailinspector/

Frequently Asked Questions

What is CVE-2026-29964? +

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. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2026-29964? +

CVE-2026-29964 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0004, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-29964? +

CVE-2026-29964 affects products from hsclabs, specifically: mailinspector. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-29964? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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