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Vulnerability Database

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A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

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A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

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Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

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355,754

Total vulnerabilities in the database

zebrad vulnerable to full node denial of service via crafted Sapling receiver in z_listunifiedreceivers — zebra-rpc

Improper Input Validation

Am I affected

You are affected if:

You run zebrad up to and including v4.4.1.
Your zebrad.toml sets rpc.listen_addr to a TCP address (RPC server is enabled).
An attacker can authenticate to the RPC endpoint. With the default enable_cookie_auth = true, this requires the attacker to read the .cookie file (typically local access). With enable_cookie_auth = false, any network client reaching the RPC port can trigger it.

Summary

The z_listunifiedreceivers RPC handler panics when processing a structurally valid Unified Address whose Sapling receiver carries 43 bytes that fail cryptographic validation (sapling_crypto::PaymentAddress::from_bytes returns None for non-subgroup Jubjub points). The handler calls .expect("using data already decoded as valid") on the fallible result. Because Zebra's release profile sets panic = "abort", the panic terminates the entire node process, not just the RPC task.

Details

zcash_address::unified::Encoding::decode validates only the structural envelope of a Unified Address (F4Jumble, bech32m, typecode ordering, 43-byte length for Sapling). It does not validate that the embedded pk_d is a valid Jubjub subgroup point or that the diversifier produces a valid g_d preimage.

At zebra-rpc/src/methods.rs:2893, the handler calls Address::try_from_sapling(network, data), which delegates to sapling_crypto::PaymentAddress::from_bytes. When from_bytes returns None (most random 32-byte strings fail the subgroup check), the .expect() fires and the process aborts.

The same crate already handles this correctly in try_from_unified at zebra-chain/src/primitives/address.rs:99-110, which returns Err when from_bytes fails. The vulnerable code path bypasses this validated route.

Patches

zebra-rpc 8.0.0 and zebrad 4.5.0.

Replace .expect() with .map_err(|e| ErrorObject::owned(...)) for proper error propagation, or route through the existing try_from_unified path which already handles this case correctly.

Workarounds

Disable the RPC server by removing rpc.listen_addr from zebrad.toml.
Ensure enable_cookie_auth = true (the default) and restrict filesystem access to the .cookie file.
Place a reverse proxy in front of the RPC port that rejects z_listunifiedreceivers calls with untrusted address parameters.

Impact

A single authenticated RPC request terminates the zebrad process. The attack is repeatable on restart (the same request triggers the same abort), allowing an attacker to keep the node down indefinitely until the request is filtered upstream. Operators using lightwalletd backends, Zaino indexers, or mining pool infrastructure that forward RPC calls to zebrad may be exposed if the forwarding path passes through z_listunifiedreceivers.

Credit

Reported by @robustfengbin via a private GitHub Security Advisory submission.

Published: Jul 2, 2026
Updated: Jul 3, 2026
GHSA: GHSA-c8w6-x74f-vmg3
Severity: Medium
Exploit:
CISA KEV:

CVSS v3:

Severity: Medium
Score: 6.5
AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWEs:

Affected Software
References

Software	From	Fixed in
zebra-rpc	-	8.0.0
zebrad	-	4.5.0

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.