XSS in Hsclabs Mailinspector
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (32.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Hsclabs Mailinspector — versions 5.3.3-7
Weakness classification (CWE)
References
- hsclabs.com/pt-br/mailinspector/ (Product)
- github.com/sql3t0/cve-disclosures (Third Party Advisory)
- github.com/sql3t0/cve-disclosures/blob/main/03_-_CVE-2026-29964_XSS.md (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-29964?
- CVE-2026-29964 is a medium-severity vulnerability in Hsclabs Mailinspector, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-05-18.
- How severe is CVE-2026-29964?
- Medium severity. CVSS v3 base score is 6.1 out of 10.