CVE-2021-42766
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to...
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (long-range consensus chain reorganizations), even when this adversary has little stake and cannot influence network message propagation. This can cause a protocol stall, or an increase in the profits of individual validators.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (long-range consensus chain reorganizations), even when this adversary has little stake and cannot influence network message propagation. This can cause a protocol stall, or an increase in the profits of individual validators.
- Record
CVE-2021-42766- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:P - Updated
- 2026-11-02
CVE List No score
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (long-range consensus chain reorganizations), even when this adversary has little stake and cannot influence network message propagation. This can cause a protocol stall, or an increase in the profits of individual validators.
- Record
CVE-2021-42766- Updated
- 2026-11-02
EUVDEUVD-2021-29724 No score
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (long-range consensus chain reorganizations), even when this adversary has little stake and cannot influence network message propagation. This can cause a protocol stall, or an increase in the profits of individual validators.
- Record
EUVD-2021-29724- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xh87-56v2-2mrp No score
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to...
The Proof-of-Stake (PoS) Ethereum consensus protocol through 2021-10-19 allows an adversary to cause a denial of service (long-range consensus chain reorganizations), even when this adversary has little stake and cannot influence network message propagation. This can cause a protocol stall, or an increase in the profits of individual validators.
- Record
GHSA-xh87-56v2-2mrp- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-42766 is a critical vulnerability (CVSS 9.1) in Proof-of-stake Ethereum Project Ethereum, published October 20, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.96%, the 61st percentile. No source names a fixed version.