CometBFT allows a malicious peer to stall the network by disseminating seemingly valid block parts

Exploitation

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

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Name: ASA-2025-002: Malicious peer can stall network by disseminating seemingly valid block parts Component: CometBFT Criticality: High (Catastrophic Impact; Possible Likelihood per ACMv1.2) Affected versions: <= v0.38.16, v1.0.0 Affected users: Validators, Full nodes, Users Description A bug was identified in the CometBFT validation of block part indices and the corresponding proof part indices that can lead to incorrect processing and dissemination of invalid parts, which in turn could lead to a network halt. Additional validation was added to prevent this condition from happening. Patches The new CometBFT releases v1.0.1 and v0.38.17 fix this issue. Unreleased code in the main branch is patched as well. Workarounds There are no known workarounds for this issue. If a node is producing these malicious proofs, the only mitigation is to upgrade CometBFT. After upgrading, the validators then will eventually conclude the correct value. Technical Deep-Dive When the next proposer creates…

Published by the source

3 Feb 2025, 16:48 UTC

Last modified by the source

5 Feb 2025, 16:34 UTC

Source last checked

26 Oct 2026, 15:08 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-r3r4-g7hq-pq4f

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# Patch Next advisory brief: GHSA-r3r4-g7hq-pq4f

Advisory: CometBFT allows a malicious peer to stall the network by disseminating seemingly valid block parts
IDs: GHSA-r3r4-g7hq-pq4f
Record: https://patchnext.com/advisories/ghsa-r3r4-g7hq-pq4f (revision 1, source checked 26 Oct 2026, 15:08 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/cometbft/cometbft 1.0.1, 0.38.17. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/cometbft/cometbft: affected >= 1.0.0-alpha.1, < 1.0.1; < 0.38.17; fixed in 0.38.17, 1.0.1

## Suggested inspection (read-only)
- Go github.com/cometbft/cometbft: 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/cometbft/cometbft.
- 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-r3r4-g7hq-pq4f (GitHub-reviewed advisory GHSA-r3r4-g7hq-pq4f lists affected ranges: Go github.com/cometbft/cometbft >=1.0.0-alpha.1 =0 <0.38.17)

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