CVE-2026-104431

Description

Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.

CVSS Vector

References

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-84j3-rw4c-gqmj
• https://www.vulncheck.com/advisories/zebra-before-6.0.0-denial-of-service-via-synchronous-script-ffi-verification