ZEBRA: Persistent on-disk corruption of Sapling/Orchard subtree roots after chain fork via pop_tip
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, a natural or attacker-influenced chain fork can leave stale Sapling and Orchard note-commitment subtree roots in Zebra state. In zebra-state/src/service/non_finalized_state/chain.rs, Chain::pop_tip removed a reverted tip block but did not remove subtree entries whose end_height belonged to that block, unlike the cleanup performed by pop_root. When the winning fork later finalized, the abandoned branch's stale subtree data could be written to RocksDB and survive node restarts. The corrupted history can cause z_getsubtreesbyindex consumers such as lightwalletd and light wallets to receive incorrect subtree roots, producing wallet synchronization failures or incorrect wallet state and requiring a full state rebuild for recovery. This issue is fixed in version 4.5.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ZcashFoundation | zebra | before 4.5.0 | 4.5.0 | Patch available | CNA |
| ZcashFoundation | zebra-state | before 7.0.0 | 7.0.0 | Patch available | CNA |
| — | zebra-state (crates.io) | before 7.0.0 | 7.0.0 | Patch available | GHSA-2gf8-q9rr-jq3h |
| — | zebrad (crates.io) | before 4.5.0 | 4.5.0 | Patch available | GHSA-2gf8-q9rr-jq3h |
- zebra VendorZcashFoundation Affected before 4.5.0 Fixed in 4.5.0 Patch available CNA
- zebra-state VendorZcashFoundation Affected before 7.0.0 Fixed in 7.0.0 Patch available CNA
- zebra-state (crates.io) Vendor— Affected before 7.0.0 Fixed in 7.0.0 Patch available GHSA-2gf8-q9rr-jq3h
- zebrad (crates.io) Vendor— Affected before 4.5.0 Fixed in 4.5.0 Patch available GHSA-2gf8-q9rr-jq3h
Remediation
- Fix · CNA zebra (ZcashFoundation) Fixed in 4.5.0
- Fix · CNA zebra-state (ZcashFoundation) Fixed in 7.0.0
- Fix · GHSA-2gf8-q9rr-jq3h zebra-state (crates.io) Fixed in 7.0.0 Advisory →
- Fix · GHSA-2gf8-q9rr-jq3h zebrad (crates.io) Fixed in 4.5.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-52733
- 2026-10-03 Alias added: GHSA-2gf8-q9rr-jq3h
References
More ZcashFoundation vulnerabilities
- TI-2026-66079 Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling CVSS 4.0HIGH 8.3
- TI-2026-37850 ZEBRA: Mempool transaction admission denial via single-peer inbound queue saturation CVSS 3.1MEDIUM 5.3
- TI-2026-71182 Improper block validation in Zebra gossip lets peers drop new blocks CVSS 4.0MEDIUM 6.3
- TI-2026-29537 Zebra: addr/addrv2 Deserialization Resource Exhaustion CVSS 4.0MEDIUM 6.3
- TI-2026-86702 Incomplete cleanup in Zebra lets peers stall initial sync CVSS 4.0HIGH 8.7
- TI-2026-86701 Quadratic signature hashing in Zcash Zebra enables denial of service CVSS 4.0HIGH 8.7
Sources
- CVE-2026-52733 · CVE Program
- CVE-2026-52733 · NVD
- FIRST EPSS
- GHSA-2gf8-q9rr-jq3h · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences