CVE-2026-44500 ZEBRA: Allocation Amplification in Inbound Network Deserializers

What is CVE-2026-44500?

CVE-2026-44500 is a medium-severity denial of service vulnerability in ZcashFoundation zebra, published on 8 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.4.0, prior to zebra-chain version 7.0.0, and prior to zebra-network version 6.0.0, 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. This issue has been patched in zebrad version 4.4.0, zebra-chain version 7.0.0, and zebra-network version 6.0.0.

Weakness: CWE-770

Which versions are affected by CVE-2026-44500?

6 open source packages ship an affected version, including zebra-chain, zebra-network and zebrad. It affects 3 products.

Products include Zfnd Zebra-Chain, Zfnd Zebra-Network, Zfnd Zebrad.

How do I fix CVE-2026-44500?

Upgrade zebra-chain to 7.0.0 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-44500 being exploited?

There is no known exploitation of CVE-2026-44500 in the wild and no public exploit code.

Other vulnerabilities in ZcashFoundation zebra

• CVE-2026-41584 ZEBRA: rk Identity Point Panic in Transaction Verification Critical 9.2

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-438q-jx8f-cccv.