CVE-2026-44497: CWE-347: Improper Verification of Cryptographic Signature in ZcashFoundation zebra
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.
AI Analysis
Technical Summary
Zebra, a Zcash node implementation written in Rust, had a vulnerability (CVE-2026-44497) caused by improper error handling in signature hash type verification during sighash computation. Specifically, when an invalid sighash type was processed, the software failed to return an error and continued with the previous valid sighash in the buffer, potentially accepting invalid signatures. This behavior could lead to consensus divergence between Zebra nodes and the reference zcashd nodes. The issue was introduced as a side effect of a previous fix (CVE-2026-41583) and affects zebrad versions before 4.4.0 and zebra-script versions before 6.0.0. The vulnerability has been addressed in the stated versions.
Potential Impact
The vulnerability can cause Zebra nodes to accept invalid signature hash types, leading to a consensus split with zcashd nodes. This consensus divergence undermines the integrity and reliability of the blockchain network as nodes disagree on transaction validity. The CVSS 4.0 score is 9.3 (critical), indicating a high impact with network attack vector, no privileges or user interaction required, and high impact on integrity and availability.
Mitigation Recommendations
This vulnerability has been patched in zebrad version 4.4.0 and zebra-script version 6.0.0. Users and operators of Zebra nodes should upgrade to these versions or later to remediate the issue. Patch status is confirmed by the vendor advisory information embedded in the description. No additional mitigation steps are indicated.
CVE-2026-44497: CWE-347: Improper Verification of Cryptographic Signature in ZcashFoundation zebra
Description
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Zebra, a Zcash node implementation written in Rust, had a vulnerability (CVE-2026-44497) caused by improper error handling in signature hash type verification during sighash computation. Specifically, when an invalid sighash type was processed, the software failed to return an error and continued with the previous valid sighash in the buffer, potentially accepting invalid signatures. This behavior could lead to consensus divergence between Zebra nodes and the reference zcashd nodes. The issue was introduced as a side effect of a previous fix (CVE-2026-41583) and affects zebrad versions before 4.4.0 and zebra-script versions before 6.0.0. The vulnerability has been addressed in the stated versions.
Potential Impact
The vulnerability can cause Zebra nodes to accept invalid signature hash types, leading to a consensus split with zcashd nodes. This consensus divergence undermines the integrity and reliability of the blockchain network as nodes disagree on transaction validity. The CVSS 4.0 score is 9.3 (critical), indicating a high impact with network attack vector, no privileges or user interaction required, and high impact on integrity and availability.
Mitigation Recommendations
This vulnerability has been patched in zebrad version 4.4.0 and zebra-script version 6.0.0. Users and operators of Zebra nodes should upgrade to these versions or later to remediate the issue. Patch status is confirmed by the vendor advisory information embedded in the description. No additional mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-06T18:28:20.886Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69fdff95cbff5d8610e6d706
Added to database: 5/8/2026, 3:21:57 PM
Last enriched: 5/8/2026, 3:36:33 PM
Last updated: 5/8/2026, 9:56:34 PM
Views: 6
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