Zebra Vulnerable to Allocation Amplification in Inbound Network Deserializers

Exploitation

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

CVSS

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

EPSS

• CVE-2026-44500: 0.36% estimated exploitation activity in the next 30 days; percentile 30.12 (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.

CVE-2026-44500: Allocation Amplification in Inbound Network Deserializers Summary Several inbound deserialization paths in Zebra allocated buffers sized against generic transport or block-size ceilings before the tighter protocol or consensus limits were enforced. An unauthenticated or post-handshake peer could therefore force the node to preallocate and parse for orders of magnitude more data than the protocol intended, across headers messages, equihash solutions in block headers, Sapling spend vectors in V5/V4 transactions, and coinbase script bytes in blocks. Severity Moderate - This is a Denial-of-Service Vulnerability that could allow a malicious peer to amplify per-message memory and parse cost on Zebra nodes, with effects amplified by multi-peer fan-in. Each individual case is bounded by the 2 MiB transport ceiling or the block-size cap, so no single message causes unbounded allocation, but the cumulative gap between intended and actual limits is significant. Affected Versions…

Published by the source

7 May 2026, 20:55 UTC

Last modified by the source

13 May 2026, 13:28 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-438q-jx8f-cccv

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# Patch Next advisory brief: CVE-2026-44500

Advisory: Zebra Vulnerable to Allocation Amplification in Inbound Network Deserializers
IDs: CVE-2026-44500, GHSA-438q-jx8f-cccv
Record: https://patchnext.com/advisories/cve-2026-44500 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: zebra-chain 7.0.0; zebra-network 6.0.0; zebrad 4.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io zebra-chain: affected <= 6.0.3; fixed in 7.0.0
- crates.io zebra-network: affected <= 5.0.2; fixed in 6.0.0
- crates.io zebrad: affected < 4.4.0; fixed in 4.4.0

## Suggested inspection (read-only)
- crates.io zebra-chain: check the installed version with your package manager.
- crates.io zebra-network: check the installed version with your package manager.
- crates.io zebrad: 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 zebra-chain, zebra-network, zebrad.
- 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-438q-jx8f-cccv (GitHub-reviewed advisory GHSA-438q-jx8f-cccv lists affected ranges: crates.io zebra-network >=0 =0 =0 <=6.0.3)

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