CVE-2026-123556

Name of the Vulnerable Software and Affected Versions ZcashFoundation Zebra versions 4.5.0 through 6.9.9

Description A protection mechanism failure allows attackers to cause lagging nodes to ban honest relaying peers for 24 hours or until a restart. This occurs because the system scores mempool lock-time rejections at the ban threshold. An attacker can trigger this by broadcasting transactions locked until the current height immediately after each block.

Recommendations Update ZcashFoundation Zebra to version 7.0.0 or later.