Authentication bypass by capture-replay in github.com/cosmos/ethermint

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2021-25835: 1.32% estimated exploitation activity in the next 30 days; percentile 70.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Cosmos Network Ethermint <= v0.4.0 is affected by a cross-chain transaction replay vulnerability in the EVM module. Since ethermint uses the same chainIDEpoch and signature schemes with ethereum for compatibility, a verified signature in ethereum is still valid in ethermint with the same msg content and chainIDEpoch, which enables "cross-chain transaction replay" attack. Specific Go Packages Affected github.com/cosmos/ethermint/rpc/namespaces/eth

Published by the source

15 Feb 2022, 01:57 UTC

Last modified by the source

2 Oct 2023, 11:32 UTC

Source last checked

26 Oct 2026, 14:59 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x5f3-qmwj-4f84

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# Patch Next advisory brief: CVE-2021-25835

Advisory: Authentication bypass by capture-replay in github.com/cosmos/ethermint
IDs: CVE-2021-25835, GHSA-x5f3-qmwj-4f84
Record: https://patchnext.com/advisories/cve-2021-25835 (revision 1, source checked 26 Oct 2026, 14:59 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/cosmos/ethermint 0.4.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/cosmos/ethermint: affected < 0.4.1; fixed in 0.4.1

## Suggested inspection (read-only)
- Go github.com/cosmos/ethermint: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/cosmos/ethermint.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x5f3-qmwj-4f84 (GitHub-reviewed advisory GHSA-x5f3-qmwj-4f84 lists affected ranges: Go github.com/cosmos/ethermint >=0 <0.4.1)

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