CVE-2026-104424

Description

Zebra before 6.1.0 contains an incorrect calculation vulnerability in its ZIP-317 block template selector that omits header and transaction-count size from the block budget. Attackers can place valid selectable transactions in a victim miner's mempool to shape templates into oversized blocks, causing rejection and wasted proof-of-work.

CVSS Vector

References

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-95m2-vx53-v2jw
• https://www.vulncheck.com/advisories/zebra-before-6.1.0-incorrect-block-size-calculation-in-getblocktemplate