---
cve: "CVE-2020-26241"
severity: "HIGH"
cvss: 7.1
epss: "23.6%"
vendor: "Generic Security"
kev: false
exploited: false
published: "2020-11-25 02:15:11"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-02T15:36:18+02:00"
---

# CVE-2020-26241

> 7.1 HIGH

## Beschreibung

Go Ethereum, or "Geth", is the official Golang implementation of the Ethereum protocol. This is a Consensus vulnerability in Geth before version 1.9.17 which can be used to cause a chain-split where vulnerable nodes reject the canonical chain. Geth's pre-compiled dataCopy (at 0x00...04) contract did a shallow copy on invocation. An attacker could deploy a contract that writes X to an EVM memory region R, then calls 0x00..04 with R as an argument, then overwrites R to Y, and finally invokes the RETURNDATACOPY opcode. When this contract is invoked, a consensus-compliant node would push X on the EVM stack, whereas Geth would push Y. This is fixed in version 1.9.17.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 748f22c192d24082723f935afd0b0b63e7fd50f4 (Commit)

## Referenzen

- <https://blog.ethereum.org/2020/11/12/geth_security_release/>
- <https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2020-26241) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_