CVE-2026-123555

Description

Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync.

References

• https://github.com/ZcashFoundation/zebra/commit/e8db87eb69254e0d4eedd058eadd48bdfa09065a
• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-jq45-ghw5-v37x
• https://www.vulncheck.com/advisories/zebra-2.3.0-before-7.0.0-denial-of-service-via-unscored-script-verification-failures