ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ZcashFoundation | zebra | zebrad < 4.3.1; zebra-script < 5.0.2 | — | No fix listed | CNA |
| — | zebrad (crates.io) | before 4.3.1 | 4.3.1 | Patch available | GHSA-8m29-fpq5-89jj |
| — | zebra-script (crates.io) | before 5.0.2 | 5.0.2 | Patch available | GHSA-8m29-fpq5-89jj |
- zebra VendorZcashFoundation Affected zebrad < 4.3.1; zebra-script < 5.0.2 Fixed in — No fix listed CNA
- zebrad (crates.io) Vendor— Affected before 4.3.1 Fixed in 4.3.1 Patch available GHSA-8m29-fpq5-89jj
- zebra-script (crates.io) Vendor— Affected before 5.0.2 Fixed in 5.0.2 Patch available GHSA-8m29-fpq5-89jj
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:zfnd:zebra-script:*:*:*:*:*:rust:*:* | before 5.0.2 | Vulnerable | ZcashFoundation |
| cpe:2.3:a:zfnd:zebrad:*:*:*:*:*:rust:*:* | before 4.3.1 | Vulnerable | ZcashFoundation |
- cpe:2.3:a:zfnd:zebra-script:*:*:*:*:*:rust:*:* Versions before 5.0.2 Vulnerable ·ZcashFoundation
- cpe:2.3:a:zfnd:zebrad:*:*:*:*:*:rust:*:* Versions before 4.3.1 Vulnerable ·ZcashFoundation
Remediation
- Fix · GHSA-8m29-fpq5-89jj zebrad (crates.io) Fixed in 4.3.1 Advisory →
- Fix · GHSA-8m29-fpq5-89jj zebra-script (crates.io) Fixed in 5.0.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-41583
- 2026-10-03 Alias added: GHSA-8m29-fpq5-89jj
References
More ZcashFoundation Zebra-script vulnerabilities
- TI-2026-32431 ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling due to Stale Buffer CVSS 4.0CRITICAL 9.3
Sources
- CVE-2026-41583 · CVE Program
- CVE-2026-41583 · NVD
- FIRST EPSS
- GHSA-8m29-fpq5-89jj · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences