When Conn.Handshake fails during ALPN negotiation the error contains attacker controlled information (the ALPN protocols sent by the client) which is not escaped.
https://pkg.go.dev/vuln/GO-2025-4008
https://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI
https://go.dev/issue/75652
https://go.dev/cl/707776
http://www.openwall.com/lists/oss-security/2025/10/08/1
Source: Mitre, NVD
Published: 2025-10-29
Updated: 2025-11-04
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS: 0.00018