Vulnerability in Zcashfoundation Zebra
CVE-2026-44498
ZEBRA is a Zcash node written entirely in Rust. Prior to version 4.4.0, Zebra's block validator undercounts transparent signature operations against the 20000-sigop block limit (MAX_BLOCK_SIGOPS), allowing it to accept blocks that zcashd rejects with bad-blk-sigops. A miner who produces such a block can split the network: Zebra nodes follow the offending chain while zcashd nodes do not. This issue has been patched in version 4.4.0.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (30.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 30.5% 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: 0.004 · change: +0.001
Affected products
- Zcashfoundation Zebra — versions < 4.4.0
- Zfnd Zebrad
Weakness classification (CWE)
References
- github.com/ZcashFoundation/zebra/releases/tag/v4.4.0 (Release Notes)
- github.com/ZcashFoundation/zebra/security/advisories/GHSA-jv4h-j224-23cc (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-44498?
- CVE-2026-44498 is a high-severity vulnerability in Zcashfoundation Zebra, classified under Incorrect Calculation. CVSS score: 7.5/10. Published 2026-05-08.
- How severe is CVE-2026-44498?
- High severity. CVSS v3 base score is 7.5 out of 10.