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0xCERT Security Advisory 0xCERT-2026-0193
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Advisory-ID:  0xCERT-2026-0193
Severity:     Critical
Published:    2026-05-07T20:56:21.000Z
Updated:      2026-10-08T22:47:29.776Z
Chains:       n/a
URL:          https://www.0xcert.com/advisory/0xCERT-2026-0193

Title: Zebra has Consensus Divergence in Transparent Sighash Hash-Type Handling due to Stale Buffer

Summary
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Zebra has Consensus Divergence in Transparent Sighash Hash-Type Handling due to Stale Buffer. The fix for https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-8m29-fpq5-89jj introduced a separate issue due to insuficient error handling of the case where the sighash type is invalid, during sighash computation.

Details
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Summary
The fix for https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-8m29-fpq5-89jj introduced a separate issue due to insuficient error handling of the case where the sighash type is invalid, during sighash computation.

Affected
- - zebra-script (rust) <= 5.0.1 — fixed in 6.0.0
- - zebrad (rust) < 4.4.0 — fixed in 4.4.0

Severity
Critical (CVSS 9.3), as rated by the upstream advisory.

Recommended actions
- - Upgrade zebra-script to 6.0.0 or later
- - Upgrade zebrad to 4.4.0 or later

Source & attribution
This 0xCERT advisory summarises GHSA-gq4h-3grw-2rhv / CVE-2026-44497 from the GitHub Advisory Database, credited upstream to sangsoo-osec: https://github.com/advisories/GHSA-gq4h-3grw-2rhv. Details may change; refer to the original source for the authoritative record.

References
- ----------
- - https://github.com/advisories/GHSA-gq4h-3grw-2rhv
- - CVE-2026-44497
- - https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-gq4h-3grw-2rhv
- - https://github.com/ZcashFoundation/zebra/releases/tag/v4.4.0
- - https://nvd.nist.gov/vuln/detail/CVE-2026-44497

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