Zebra before 11.0.0 Denial of Service via getblock Verbosity 2
Priority LOW 37CWE-617Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-617.
Summary
The getblock RPC method in zebra-rpc before 11.0.0, used by the Zcash Foundation's Zebra node, panics on verbosity 2 for a side-chain block because the block's -1 confirmations sentinel is converted to u32 with .expect(), aborting the process. Remote unauthenticated attackers, directly or through lightwalletd, can repeat this call to keep the node in a crash loop.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00387 33rd percentileScored 2026-11-07
Fix Fixed zebra (ZcashFoundation): 11.0.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- 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 11.0.0 | 11.0.0 | Patch available | CNA |
- zebra VendorZcashFoundation Affected before 11.0.0 Fixed in 11.0.0 Patch available CNA
Remediation
- Fix · CNA zebra (ZcashFoundation) Fixed in 11.0.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-104428
- 2026-10-03 Alias added: GHSA-2qvh-q2cj-955r
- 2026-10-04 Priority changed: MEDIUM → LOW
- 2026-10-06 CISA SSVC decision points changed
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-2026-30136 ZEBRA: Consensus Divergence in Transparent Sighash Hash-Type Handling CVSS 4.0CRITICAL 9.3
- TI-2026-37853 ZEBRA: Consensus divergence via P2SH sigop undercount in pure-Rust disabled-opcode parser CVSS 4.0CRITICAL 9.3
Sources
- CVE-2026-104428 · CVE Program
- CVE-2026-104428 · NVD
- FIRST EPSS
- GHSA-2qvh-q2cj-955r · GitHub Advisory Database · CC BY 4.0
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