Zebra's Transparent SIGHASH_SINGLE Handling Diverges from zcashd for Corresponding Outputs
Zebra's Transparent SIGHASH_SINGLE Handling Diverges from zcashd for Corresponding Outputs. For V5+ transparent spends, Zebra and zcashd disagree on the same consensus rule: SIGHASHSINGLE must fail when the input index has no corresponding output. zcashd treats this as consensus-invalid under ZIP-244, while Zebra's transparent verification path computes a digest for the missing-output case instead of failing.
Vuln-watch · relayed from the GitHub Advisory Database; see Source & attribution below
Summary
For V5+ transparent spends, Zebra and zcashd disagree on the same consensus rule: SIGHASHSINGLE must fail when the input index has no corresponding output. zcashd treats this as consensus-invalid under ZIP-244, while Zebra's transparent verification path computes a digest for the missing-output case instead of failing.
Affected
- zebrad (rust) < 4.4.0 — fixed in 4.4.0
Severity
Critical (CVSS 9.2), as rated by the upstream advisory.
Recommended actions
- Upgrade zebrad to 4.4.0 or later
Source & attribution
This 0xCERT advisory summarises GHSA-cwfq-rfcr-8hmp from the GitHub Advisory Database, credited upstream to sangsoo-osec, defuse, mpguerra, upbqdn: https://github.com/advisories/GHSA-cwfq-rfcr-8hmp. Details may change; refer to the original source for the authoritative record.
References
OpenPGP-signed. The signed text of this advisory verifies against the 0xCERT key CCC7 D9EC 9415 723D.
Published 2026-05-07 · last updated 2026-10-08
curl -s https://www.0xcert.com/pgp.asc | gpg --import && curl -s https://www.0xcert.com/advisory/0xCERT-2026-0194/signed.txt | gpg --verify