Remote memory exhaustion in ckb

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.

In the ckb sync protocol, SyncState maintains a HashMap called 'misbehavior' that keeps a score of a peer's violations of the protocol. This HashMap is keyed to PeerIndex (an alias for SessionId), and entries are never removed from it. SessionId is an integer that increases monotonically with every new connection. A remote attacker can manipulate this HashMap to grow forever, resulting in degraded performance and ultimately a panic on allocation failure or being killed by the OS, depending on the platform. This is a critical severity security bug. It could be exploited to create a targeted or network-wide denial of service, to reduce the hash power of the network as part of a 51% attack, and perhaps in other creative ways. An attack is trivial: 1. connect to another node 2. send an invalid sync protocol request, such as SendHeaders for non-consecutive blocks 3. disconnect 4. repeat

Published by the source

25 Aug 2021, 21:01 UTC

Last modified by the source

11 Jan 2023, 05:05 UTC

Source last checked

26 Oct 2026, 15:33 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-48vq-8jqv-gm6f

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# Patch Next advisory brief: GHSA-48vq-8jqv-gm6f

Advisory: Remote memory exhaustion in ckb
IDs: GHSA-48vq-8jqv-gm6f
Record: https://patchnext.com/advisories/ghsa-48vq-8jqv-gm6f (revision 1, source checked 26 Oct 2026, 15:33 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: ckb 0.40.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io ckb: affected < 0.40.0; fixed in 0.40.0

## Suggested inspection (read-only)
- crates.io ckb: 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 ckb.
- 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-48vq-8jqv-gm6f (GitHub-reviewed advisory GHSA-48vq-8jqv-gm6f lists affected ranges: crates.io ckb >=0 <0.40.0)

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