GHSA-9856-9gg9-qcmq is a medium-severity (CVSS 6.5) CWE-436 vulnerability in github.com/ethereum/go-ethereum. O3 Security confirms whether GHSA-9856-9gg9-qcmq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Ethereum Contains Consensus Flaw During Block Processing
Real-World Exposure
github.com/ethereum/go-ethereumReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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
Workarounds
No workarounds exist, save to update and/or apply the patch commit.
References.
Post-mortem write-up.
Credits
The bug was found by @guidovranken (working for Sentnl during an audit of the Telos 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
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/ethereum/go-ethereum | ≥ 1.10.0&&< 1.10.8 | 1.10.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ethereum/go-ethereum. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/ethereum/go-ethereum to 1.10.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9856-9gg9-qcmq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-9856-9gg9-qcmq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-9856-9gg9-qcmq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9856-9gg9-qcmq in your dependencies?
O3 detects GHSA-9856-9gg9-qcmq across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.