CVE-2026-104428

The getblock RPC method in zebra-rpc before 11.0.0, used by the Zcash Foundation's Zebra node, panics on verbosity 2 for a side-chain block because the block's -1 confirmations sentinel is converted to u32 with .expect(), aborting the process. Remote unauthenticated attackers, directly or through lightwalletd, can repeat this call to keep the node in a crash loop.

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-x6v8-c2xp-928m
• https://www.vulncheck.com/advisories/zebra-before-11.0.0-denial-of-service-via-getblock-verbosity-2