zebra: Reachable Assertion
CVE-2026-52829 is a high-severity reachable assertion vulnerability in zebra from ZcashFoundation, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected zebra versions: < 4.5.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.61% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of zebra you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| ZcashFoundation | zebra | < 4.5.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Reachable Assertion
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
How developers prevent this class of flaw
- If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
- Consider changing the assertion to some other less fatal error. This might not be easy to implement, since other code may be needed to handle the error.
- Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in zebra
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Reachable Assertion vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
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