🛡️ CVE-2021-39137 — go-ethereum

⚪ Unknown ✅ No Known Exploit CWE-436 OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Ethereum Contains Consensus Flaw During Block Processing

Impact

A vulnerability in the Geth EVM could cause a node to reject the canonical chain.

Description

A memory-corruption bug within the EVM can cause a consensus error, where vulnerable nodes obtain a different stateRoot when processing a maliciously crafted transaction. This, in turn, would lead to the chain being split in two forks.

All Geth versions supporting the London hard fork are vulnerable (which predates London), so all users should update.

This bug was exploited on Mainnet at block 13107518, leading to a minority chain split.

Patches

A patch is included in the v1.10.8 release.

The exact patch to fix the issue is contained within this [commit](https://github.com/ethereum/go-ethereum/pull/23381/commits/4d4879cafd1b3c906fc184a8c4a357137465128f)

Workarounds

No workarounds exist, save to update and/or apply the patch commit.

References.

Post-mortem [write-up](https://github.com/ethereum/go-ethereum/blob/master/docs/postmortems/2021-08-22-split-postmortem.md).

Credits

The bug was found by @guidovranken (working for [Sentnl](https://sentnl.io/) during an audit of the [Telos EVM](https://www.telos.net/evm)) and reported via [email protected].

For more information

If you have any questions or comments about this advisory:

  • Open an issue in [go-ethereum](https://github.com/ethereum/go-ethereum/)
  • Email us at [security@ethereum.org](mailto:[email protected])

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Weakness class

CVE-2021-39137 is classified as CWE-436: Interpretation Conflict. Two components parse the same data differently, so a check in one is bypassed in the other.

Affected software

CVE-2021-39137 is recorded against 1 package.

  • github.com/ethereum/go-ethereum

Timeline and source

Published on 30 August 2021 and last revised on 8 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
github.com (Web)
pkg.go.dev (Web)

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE CWE-436
Public Exploit ✅ No
Source OSV
Published 2021-08-30
Updated 2026-08-12
Modified 2026-07-08

Affected Packages

Software From version Fixed in
github.com/ethereum/go-ethereum — —

Similar Threats

Free Vulnerability Check

Is your site affected by CVE-2021-39137?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against CVE-2021-39137 and other known CVE records.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.