---
cve: "CVE-2026-63382"
severity: "CRITICAL"
cvss: 9.2
epss: "0.6%"
vendor: "libevent"
kev: false
exploited: false
published: "2026-08-20 18:16:35"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-28T03:29:07+02:00"
---

# CVE-2026-63382

> 9.2 CRITICAL · 🧪 PoC

## Beschreibung

Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- df3ecad3a040fd6d4fad4287defe113395de6fd7 (Commit)
- 79ddfb460847999b807cba76d04e73891f29c6ee (Commit)

## BSI-Hinweise (deutsch)

- [Red Hat Enterprise Linux (corosync, libevent, libsoup): Mehrere Schwachstellen](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-3419) — _BSI-Einstufung: hoch_
  Ein Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder Denial-of-Service-Zustände herbeizuführen.

## Referenzen

- <https://github.com/libevent/libevent/security/advisories/GHSA-q39v-w2g7-gr8j>
- <https://github.com/libevent/libevent/commit/10abb34b8dc3e1184de315dd261ce4b77563cda6>
- <https://github.com/libevent/libevent/commit/5119ceb00557bf007f9065709e852686f3c0bb6e>
- <https://github.com/libevent/libevent/commit/83ba67373032334559b82409db035dd8c3cc1660>
- <https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0>
- <https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable>
- <https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-63382) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_