---
title: "CVE-2026-44497: Zebra has Consensus Divergence in Transparent Sighash Hash-Type Handling due to Stale Buffer"
url: https://erroneo.us/security/cve/CVE-2026-44497/
description: "CVE-2026-44497 (zebra-script (crates.io (Rust))): ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.4.0 and prior to zebra-script…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-08
date_modified: 2026-05-13
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-44497"
kev: false
cvss: 9.3
epss: 0.00297
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-44497: Zebra has Consensus Divergence in Transparent Sighash Hash-Type Handling due to Stale Buffer

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.3% , percentile 21: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 21% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes zebra-script (crates.io (Rust)) <= 5.0.1, fixed in 6.0.0 ; zebrad (crates.io (Rust)) < 4.4.0, fixed in 4.4.0 . Check your lockfile, including transitive dependencies.

## What it is

ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.4.0 and prior to zebra-script version 6.0.0, the fix for CVE-2026-41583 introduced a separate issue due to insufficient error handling of the case where the sighash type is invalid, during sighash computation. Instead of returning an error, the normal flow would resume, and the input sighash buffer would be left untouched. In scenarios where a previous signature validation could leave a valid sighash in the buffer, an invalid hash-type could be incorrectly accepted, which would create a consensus split between Zebra and zcashd nodes. This issue has been patched in zebrad version 4.4.0 and zebra-script version 6.0.0.

## Affected packages

- crates.io (Rust) `zebra-script` <= 5.0.1 → fixed: 6.0.0
- crates.io (Rust) `zebrad` < 4.4.0 → fixed: 4.4.0

## Affected products (CVE record)

- ZcashFoundation zebra: zebra-script < 6.0.0, zebrad < 4.4.0

## Severity

- GitHub_M CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H`
- GitHub CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.30% probability of exploitation activity in the next 30 days; percentile 21.

## Sources

- [GitHub Advisory GHSA-gq4h-3grw-2rhv](https://github.com/advisories/GHSA-gq4h-3grw-2rhv)
- [CVE.org record CVE-2026-44497](https://www.cve.org/CVERecord?id=CVE-2026-44497)
- [NVD entry CVE-2026-44497](https://nvd.nist.gov/vuln/detail/CVE-2026-44497)
- [github.com](https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-gq4h-3grw-2rhv)
- [github.com](https://github.com/ZcashFoundation/zebra/releases/tag/v4.4.0)

---
Source page: https://erroneo.us/security/cve/CVE-2026-44497/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt