ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling due to Stale Buffer
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-347.
Summary
ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.4.0 and prior to zebra-script version 6.0.0, the fix for CVE-2026-41583 introduced a separate issue due to insufficient error handling of the case where the sighash type is invalid, during sighash computation. Instead of returning an error, the normal flow would resume, and the input sighash buffer would be left untouched. In scenarios where a previous signature validation could leave a valid sighash in the buffer, an invalid hash-type could be incorrectly accepted, which would create a consensus split between Zebra and zcashd nodes. This issue has been patched in zebrad version 4.4.0 and zebra-script version 6.0.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
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 | zebra-script < 6.0.0; zebrad < 4.4.0 | — | No fix listed | CNA |
| — | zebra-script (crates.io) | before 6.0.0 | 6.0.0 | Patch available | GHSA-gq4h-3grw-2rhv |
| — | zebrad (crates.io) | before 4.4.0 | 4.4.0 | Patch available | GHSA-gq4h-3grw-2rhv |
- zebra VendorZcashFoundation Affected zebra-script < 6.0.0; zebrad < 4.4.0 Fixed in — No fix listed CNA
- zebra-script (crates.io) Vendor— Affected before 6.0.0 Fixed in 6.0.0 Patch available GHSA-gq4h-3grw-2rhv
- zebrad (crates.io) Vendor— Affected before 4.4.0 Fixed in 4.4.0 Patch available GHSA-gq4h-3grw-2rhv
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:zfnd:zebra-script:*:*:*:*:*:rust:*:* | before 6.0.0 | Vulnerable | ZcashFoundation |
| cpe:2.3:a:zfnd:zebrad:*:*:*:*:*:rust:*:* | before 4.4.0 | Vulnerable | ZcashFoundation |
- cpe:2.3:a:zfnd:zebra-script:*:*:*:*:*:rust:*:* Versions before 6.0.0 Vulnerable ·ZcashFoundation
- cpe:2.3:a:zfnd:zebrad:*:*:*:*:*:rust:*:* Versions before 4.4.0 Vulnerable ·ZcashFoundation
Remediation
- Fix · GHSA-gq4h-3grw-2rhv zebra-script (crates.io) Fixed in 6.0.0 Advisory →
- Fix · GHSA-gq4h-3grw-2rhv zebrad (crates.io) Fixed in 4.4.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-44497
- 2026-10-03 Alias added: GHSA-gq4h-3grw-2rhv
References
More ZcashFoundation Zebra-script vulnerabilities
- TI-2026-30136 ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling CVSS 4.0CRITICAL 9.3
Sources
- CVE-2026-44497 · CVE Program
- CVE-2026-44497 · NVD
- FIRST EPSS
- GHSA-gq4h-3grw-2rhv · GitHub Advisory Database · CC BY 4.0
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