CVE-2026-52829 ZEBRA: IPv4-Mapped Mempool Misbehavior Update Aborts Zebra Address Book
An unauthenticated peer can crash a synced Zebra node by triggering an assertion failure during mempool misbehavior updates.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52829?
CVE-2026-52829 is a high-severity denial of service vulnerability in ZcashFoundation zebra, published on 18 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, an unauthenticated IPv4 peer can deterministically terminate a synced Zebra node using the default Linux dual-stack listener configuration. The handshake path canonicalized an IPv4-mapped IPv6 PeerSocketAddr such as ::ffff:127.0.0.1 to plain IPv4 before storing it through MetaAddr::new_connected, but the mempool misbehavior path forwarded the raw transient address to MetaAddrChange::UpdateMisbehavior. In zebra-network/src/meta_addr.rs, apply_to_meta_addr then compared the canonical address-book entry with the raw update address and reached its unexpected address mismatch assertion. After the misbehavior batch flush, panic equals abort terminated zebrad; the peer only needed to complete a P2P handshake and advertise an invalid mempool transaction. This issue is fixed in version 4.5.0.
Which versions are affected by CVE-2026-52829?
4 open source packages ship an affected version, including zebra-network and zebrad.
| Package | Affected | Fixed in |
|---|---|---|
zebra-network crates.io | All versions | 7.0.0 |
zebra-network crates.io | All versions | 7.0.0 |
zebrad crates.io | All versions | 4.5.0 |
zebrad crates.io | All versions | 4.5.0 |
How do I fix CVE-2026-52829?
Upgrade zebra-network to 7.0.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-52829 being exploited?
There is no known exploitation of CVE-2026-52829 in the wild and no public exploit code.
Sources
Also known as GHSA-63wg-wjjj-7cp8.