Zebra's Block Validator Undercounts Coinbase and P2SH Sigops

ZcashFoundation zebra

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.

First seen: 7 May 2026
Last update: 7 May 2026, 20:54 UTC
Versions per GitHub advisory, not the vendor: zebrad 4.4.0
zebra 4.4.0
Identifiers: CVE-2026-44498
CVSS: 9.2
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 Block Validator Undercounts Coinbase and P2SH Sigops
Severity: critical. Patch status: fix status unknown.
Affected: ZcashFoundation zebra
Versions per GitHub advisory, not the vendor: zebrad 4.4.0, zebra 4.4.0
Ids: CVE-2026-44498

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.

## 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, zebra 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. zebra: 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 |
| zebra | per the CVE record from GitHub_M, 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("CVE-2026-44498") 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-jv4h-j224-23cc https://github.com/advisories/GHSA-jv4h-j224-23cc https://nvd.nist.gov/vuln/detail/CVE-2026-44498
https://pwned.coffee/i/zebra-s-block-validator-undercounts-coinbase-and-p2sh-si-cve-2026-44498

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
zebra before 4.4.0 4.4.0 CVE record (CNA) per the CVE record from GitHub_M, not the vendor checked 13 Nov
Score: CVSS 9.2 (critical). CVSS 4.0 9.2 (CNA GitHub_M) for CVE-2026-44498
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
zebra	before 4.4.0	4.4.0	CVE record (CNA) per the CVE record from GitHub_M, not the vendor checked 13 Nov

Sources: KEV – CVE record ✓ Vendor –

Sources

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