Vulnerability in Zcashfoundation Zebra
CVE-2026-41583
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (39.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Zcashfoundation Zebra — versions zebrad < 4.3.1, zebra-script < 5.0.2
- Zfnd Zebrad
- Zfnd Zebra-Script
Weakness classification (CWE)
References
- github.com/ZcashFoundation/zebra/security/advisories/GHSA-8m29-fpq5-89jj (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-41583?
- CVE-2026-41583 is a critical-severity vulnerability in Zcashfoundation Zebra, classified under CWE-573. CVSS score: 9.1/10. Published 2026-05-08.
- How severe is CVE-2026-41583?
- Critical severity. CVSS v3 base score is 9.1 out of 10.