go runtime_error ai_generated true

net/http: invalid header field value for "X-Custom-Header"

ID: go/http-header-value-invalid

Also available as: JSON · Markdown · 中文
80%Fix Rate
83%Confidence
0Evidence
2024-04-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.21 active — — —

Root Cause

Header values contain characters not allowed by HTTP spec (e.g., newlines, control chars), causing WriteHeader to fail.

generic

中文

头部值包含HTTP规范不允许的字符（如换行、控制字符），导致WriteHeader失败。

Workarounds

  1. 90% success 
    Use httpguts.ValidHeaderFieldValue to validate before setting
  2. 85% success 
    Sanitize input by stripping invalid characters: strings.Map(func(r rune) rune { if r < 32 || r > 126 { return -1 }; return r }, val)

Dead Ends

Common approaches that don't work:

  1. 60% fail

    Escaping may change semantics; proper sanitization needed

  2. 40% fail

    May break client expectations if header is required