Denial of service in github.com/ethereum/go-ethereum

Exploitation

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

CVSS

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

EPSS

• CVE-2020-26264: 1.89% estimated exploitation activity in the next 30 days; percentile 79.54 (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.

Impact A DoS vulnerability can make a LES server crash via malicious GetProofsV2 request from a connected LES client. Patches The vulnerability was patched in https://github.com/ethereum/go-ethereum/pull/21896. Workarounds This vulnerability only concerns users explicitly enabling les server; disabling les prevents the exploit. It can also be patched by manually applying the patch in https://github.com/ethereum/go-ethereum/pull/21896. For more information If you have any questions or comments about this advisory: Open an issue in go-ethereum Email us at security@ethereum.org

Published by the source

29 Jun 2021, 21:14 UTC

Last modified by the source

14 Feb 2023, 21:38 UTC

Source last checked

26 Oct 2026, 14:55 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-r33q-22hv-j29q

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# Patch Next advisory brief: CVE-2020-26264

Advisory: Denial of service in github.com/ethereum/go-ethereum
IDs: CVE-2020-26264, GHSA-r33q-22hv-j29q
Record: https://patchnext.com/advisories/cve-2020-26264 (revision 1, source checked 26 Oct 2026, 14:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/ethereum/go-ethereum 1.9.25. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/ethereum/go-ethereum: affected < 1.9.25; fixed in 1.9.25

## Suggested inspection (read-only)
- Go github.com/ethereum/go-ethereum: 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/ethereum/go-ethereum.
- 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-r33q-22hv-j29q (GitHub-reviewed advisory GHSA-r33q-22hv-j29q lists affected ranges: Go github.com/ethereum/go-ethereum >=0 <1.9.25)

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