CVE-2026-527375.3MediumCWE-345

CVE-2026-52737: ZEBRA: Sync restart poisoning from single unauthenticated peer via above-lookahead block

ZcashFoundation · zebra

Affected: ZcashFoundation zebra · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.3%probability of exploitation in the next 30 days

18th percentile

050100

Higher than 18% of scored CVEs

5.3MediumCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, a malicious unauthenticated P2P peer can answer Zebra's outbound getblocks or FindBlocks request with a small two-hash inventory and then serve a syntactically valid block whose coinbase height is far above the local chain tip. In zebrad/src/components/sync/downloads.rs, BlockDownloadVerifyError::AboveLookaheadHeightLimit originally carried only the block height and hash, so handle_block_response could not attribute the failure to the advertising peer. The error then reached the restart-worthy default path in zebrad/src/components/sync.rs, cancelling all in-flight downloads from honest peers and imposing a 67-second sync restart delay on mainnet. Because the peer was neither scored nor disconnected, the peer could repeat the cycle indefinitely with minimal bandwidth and significantly degrade synchronization without corrupting state. This issue is fixed in version 4.5.0.

Affected products2

From the CVE record. A product or version that is not listed is unknown, not unaffected.

ZcashFoundation · zebra< 4.5.0
ZcashFoundation · zebra-consensus< 7.0.0

On the Atlas

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Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Insufficient Verification of Data Authenticity · Cryptography
Vendor: ZcashFoundation
Published: August 2026
Band: Unlikely (under 1%), August 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-52737 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.