Medium (6.5) in golang go. EPSS 1.5% chance of exploitation in the next 30 days. Fixed in stdlib 1.17.12, 1.18.4.
Acceptance of some invalid Transfer-Encoding headers in the HTTP/1 client in net/http before Go 1.17.12 and Go 1.18.4 allows HTTP request smuggling if combined with an intermediate server that also improperly fails to reject the header as invalid.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS
1.5% chance of exploitation in the next 30 days; higher than 74% of CVEs (scores of 2026-10-31)