---
cve: "CVE-2026-77639"
severity: "MEDIUM"
cvss: 5.3
epss: "0.2%"
vendor: "torproject"
kev: false
exploited: false
published: "2026-08-20 21:17:11"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T20:06:29+02:00"
---

# CVE-2026-77639

> 5.3 MEDIUM

## Beschreibung

Tor before 0.4.9.9 was prone to a compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 74b53bd1992da4eca7a89668d9a1a040faff7a73 (Commit)

## Referenzen

- <https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-77639) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_