Description
When Conn.Handshake fails during ALPN negotiation the error contains attacker controlled information (the ALPN protocols sent by the client) which is not escaped.
Affected products
golang: go
References5
- pkg.go.dev/vuln/GO-2025-4008 Vendor Advisory
- go.dev/cl/707776 Patch
- go.dev/issue/75652 Issue Tracking
- groups.google.com/g/golang-announce/c/4Emdl2iQ_bI Mailing ListRelease Notes
- www.openwall.com/lists/oss-security/2025/10/08/1 Mailing ListRelease NotesThird Party Advisory
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 41 · as of 10 November 2026
- CWE
- CWE-532
Could this be exploited in your environment?
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