What’s Vulnerable › Vulnerabilities

CVE-2021-3646: Cross-site Scripting (XSS) - Reflected in btcpayserver/btcpayserver

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-09-10 · updated 2026-06-17
• Weakness: CWE-79

Description

btcpayserver is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected products

• btcpayserver/btcpayserver: before 1.2.3 — fixed in 1.2.3

How to fix

Upgrade to a fixed version: btcpayserver/btcpayserver 1.2.3. Check the vendor advisory for mitigations.

References

• https://github.com/btcpayserver/btcpayserver/commit/fc4e47cec608cc3dba24b19d0145ac69320b975e
• https://huntr.dev/bounties/32e30ecf-31fa-45f6-8552-47250ef0e613
• https://github.com/btcpayserver/btcpayserver/commit/fc4e47cec608cc3dba24b19d0145ac69320b975e
• https://huntr.dev/bounties/32e30ecf-31fa-45f6-8552-47250ef0e613

Get alerted when CVE-2021-3646 or the next vulnerability affects your stack