---
cve: "CVE-2026-45372"
severity: "CRITICAL"
cvss: 9.9
epss: "30%"
vendor: "yhirose"
kev: false
exploited: false
published: "2026-05-29 20:16:26"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-05T22:22:32+02:00"
---

# CVE-2026-45372

> 9.9 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- 811dd0b6f2382f50f801f3cfdb5ba349d08bb575 (Commit)

## Referenzen

- <https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4m>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-45372) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_