Vulnerability · Published May 8, 2026 · Assigned by GitHub_M
CVE-2026-41583ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling
Critical 9.3
In plain English
A critical-severity security flaw in zebra from ZcashFoundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Official description
ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and prior to zebra-script version 5.0.2, after a refactoring, Zebra failed to validate a consensus rule that restricted the possible values of sighash hash types for V5 transactions which were enabled in the NU5 network upgrade. Zebra nodes could thus accept and eventually mine a block that would be considered invalid by zcashd nodes, creating a consensus split between Zebra and zcashd nodes. In a similar vein, for V4 transactions, Zebra mistakenly used the "canonical" hash type when computing the sighash while zcashd (correctly per the spec) uses the raw value, which could also crate a consensus split. This issue has been patched in zebrad version 4.3.1 and zebra-script version 5.0.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ZcashFoundation | zebra | zebrad < 4.3.1zebra-script < 5.0.2 |
Weakness: CWE-573 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H
References
- https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-8m29-fpq5-89jj x_refsource_CONFIRM