---
cve: "CVE-2026-77762"
severity: "HIGH"
cvss: 8.1
epss: "0.4%"
vendor: "Apache Software Foundation"
kev: false
exploited: false
published: "2026-09-23 12:17:06"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-10-02T21:27:23+02:00"
---

# CVE-2026-77762

> 8.1 HIGH

## Beschreibung

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request.



This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121.



The following versions were EOL at the time the CVE was created but are 
known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected.




Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.

## CNA-Record (Kanon, cvelistV5)

- CNA: **apache**
- State: PUBLISHED
- Stand: 2026-09-30 14:50:02

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **total**

## CVSS-Vektor

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

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

## BSI-Hinweise (deutsch)

- [Apache Tomcat: Mehrere Schwachstellen](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-3527) — _BSI-Einstufung: mittel_
  Ein Angreifer kann mehrere Schwachstellen in Apache Tomcat ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um einen Denial of Service Angriff durchzuführen und um Daten zu manipulieren.

## Referenzen

- <https://lists.apache.org/thread/y5r9fvjo7ol24mkoyoc0st8bqrfyqcyn>
- <http://www.openwall.com/lists/oss-security/2026/09/23/23>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-77762) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_