Zebra's Transparent SIGHASH_SINGLE Handling Diverges from zcashd for Corresponding Outputs

zebrad

Zebra Transparent SIGHASH_SINGLE Corresponding-Output Handling Diverges From zcashd For V5+ transparent spends, Zebra and zcashd disagree on the same consensus rule: SIGHASH_SINGLE must fail when the input index has no corresponding output.

First seen: 7 May 2026
Last update: 7 May 2026, 21:02 UTC
Versions per GitHub advisory, not the vendor: zebrad 4.4.0
Source: GitHub advisory

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Zebra's Transparent SIGHASH_SINGLE Handling Diverges from zcashd for Corresponding Outputs
Severity: critical. Patch status: fix status unknown.
Affected: zebrad
Versions per GitHub advisory, not the vendor: zebrad 4.4.0

Zebra Transparent SIGHASH_SINGLE Corresponding-Output Handling Diverges From zcashd For V5+ transparent spends, Zebra and zcashd disagree on the same consensus rule: SIGHASH_SINGLE must fail when the input index has no corresponding output.

## Steps
1. Search every lockfile and manifest (package-lock.json, yarn.lock, pnpm-lock.yaml, requirements*.txt, poetry.lock, uv.lock, composer.lock, go.sum, Cargo.lock, Gemfile.lock) for `zebrad`. For each hit, compare the installed version with the version on the same major line (per GitHub advisory, not the vendor, so check the vendor's advisory before treating it as a fix): zebrad 4.4.0. If it's lower, give the exact upgrade command for the package manager this repo uses.
2. Versions per GitHub advisory, not the vendor: zebrad: older than 4.4.0 → 4.4.0. Don't treat them as a fix until the vendor says so.

## Fix by release line
| Line | State | Fix | Until then |
|---|---|---|---|
| zebrad older than 4.4.0 | per GitHub advisory, not the vendor | 4.4.0 | restrict network access to it |

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/ZcashFoundation/zebra/releases/tag/v4.4.0 https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-cwfq-rfcr-8hmp https://github.com/advisories/GHSA-cwfq-rfcr-8hmp
https://pwned.coffee/i/zebra-s-transparent-sighash-single-handling-diverges-from-zcashd-for-cor

Receipt

Exploitation: No known exploitation
By release line, per GitHub advisory, not the vendor: Product Affected Version named Source
zebrad (cargo) < 4.4.0 4.4.0 GitHub advisory per GitHub advisory, not the vendor checked 13 Nov
Score: GitHub advisory rating: critical. No CVSS published.
Last checked: 13 Nov 2026, 03:17 UTC

Product	Affected	Version named	Source
zebrad (cargo)	< 4.4.0	4.4.0	GitHub advisory per GitHub advisory, not the vendor checked 13 Nov

Sources: KEV – CVE record ✓ Vendor –

Sources

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