CVE-2026-41584 — zebrad
CVE-2026-41584 is a Reachable Assertion vulnerability in zebrad. A fix is available for zebrad — see the affected versions and patch details below.
ZEBRA: rk Identity Point Panic in Transaction Verification
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-41584.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
zebrad🦀zebra-chainReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
rk Identity Point Panic in Transaction Verification
Summary
Orchard transactions contain a rk field which is a randomized validating key and also an elliptic curve point. The Zcash specification allows the field to be the identity (a "zero" value), however, the orchard crate which is used to verify Orchard proofs would panic when fed a rk with the identity value. Thus an attacker could send a crafted transaction that would make a Zebra node crash.
Severity
Critical - This is a Denial of Service Vulnerability that could allow an attacker to crash Zebra nodes.
Affected Versions
All Zebra versions prior to version 4.3.1.
Description
The vulnerability exists in the circuits.rs file of the orchard crate; it attempts to get the coordinates of the rk value and calls unwrap() on the results, which causes a panic if rk is the identity.
Zebra parses rk as a byte vector; it creates an Orchard "bundle" using the orchard crate and then calls the same crate to verify it, triggering the panic.
An attacker could exploit this by:
- Creating a transaction with a identity
rk - Submitting it to a Zebra node, making it crash
Impact
Denial of Service
- Attack Vector: Network.
- Effect: Node crash.
- Scope: Any impacted Zebra node.
Fixed Versions
This issue is fixed in Zebra 4.3.1.
The fix was agreed with zcashd developers (which has the same issue) to not allow the identity rk anymore and change the specification as such. Zebra now does this when parsing a transaction. This was deemed easier than fixing the issue in orchard, which would make the bug public before the nodes could be patched.
Mitigation
Users should upgrade to Zebra 4.3.1 or later immediately.
There are no known workarounds for this issue. Immediate upgrade is the only way to ensure the node remains not vulnerable to denial of service.
Credits
Thanks to Alex “Scalar” Sol for finding and reporting the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | zebrad | all versions | 4.3.1cargo update -p zebrad --precise 4.3.1 |
| 🦀crates.io | zebra-chain | all versions | 6.0.2cargo update -p zebra-chain --precise 6.0.2 |
Affected Products
zebra-chainzfndzebradzfndDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zebrad, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zebrad to 4.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41584 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2026-41584 in your dependencies?
Find it across crates.io, including transitive dependencies.