| Summary | cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \r\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0. |
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| Publication Date | May 30, 2026, 5:16 a.m. |
| Registration Date | May 31, 2026, 4:15 a.m. |
| Last Update | May 30, 2026, 5:23 a.m. |
| CVSS3.1 : CRITICAL | |
| スコア | 9.9 |
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| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L |
| 攻撃元区分(AV) | ネットワーク |
| 攻撃条件の複雑さ(AC) | 低 |
| 攻撃に必要な特権レベル(PR) | 不要 |
| 利用者の関与(UI) | 不要 |
| 影響の想定範囲(S) | 変更あり |
| 機密性への影響(C) | 低 |
| 完全性への影響(I) | 高 |
| 可用性への影響(A) | 低 |