How severe is CVE-2026-52733?

CVE-2026-52733 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-52733?

CVE-2026-52733 affects the following packages: zebra-state (crates.io), zebrad (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2026-52733?

Update zebra-state to 7.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52733 is resolved across your whole dependency graph.

How do I detect CVE-2026-52733 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zebra-state, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-52733 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-52733 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-52733 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-52733?

CVE-2026-52733 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 37th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-52733?

CVE-2026-52733 is classified as CWE-459 (CWE-459), CWE-672 (CWE-672). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-52733 published, and has it been updated?

CVE-2026-52733 was published on August 18, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀

🦀 crates.io

Not in CISA KEV

MEDIUM severity

CVE-2026-52733 — zebra-state

MEDIUMFix: ZcashFoundation/zebra@1440b43

CVE-2026-52733 is a medium-severity (CVSS 6.5) CWE-459 vulnerability in zebra-state. A fix is available for zebra-state — see the affected versions and patch details below.

ZEBRA: Persistent on-disk corruption of Sapling/Orchard subtree roots after chain fork via pop_tip

Also known asGHSA-2gf8-q9rr-jq3h

Published

Aug 18, 2026

Updated

Oct 21, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs37th percentile — riskier than 37% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-52733 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

🦀zebra-state🦀zebrad

Real-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

Am I affected

You are affected if:

You run zebrad up to and including v4.4.1.
Your node participates in a network where chain forks occur (mainnet, testnet, or any network with multiple miners).

All default configurations are affected. The corruption persists across restarts because it is written to RocksDB.

Summary

When pop_tip removes the tip block during a chain fork, stale Sapling and Orchard note commitment subtree root data is retained in the in-memory non-finalized state. When the chain subsequently finalizes, this stale data is written to the persistent RocksDB state. The corrupted subtree root history affects z_getsubtreesbyindex (used by lightwalletd for wallet synchronization) and could affect future chain verification that depends on correct subtree roots.

Details

The non-finalized state provides two methods for removing blocks: pop_root (removes the oldest block during finalization) and pop_tip (removes the newest block during a fork revert). pop_root correctly cleans up note commitment subtree contributions. pop_tip does not: it removes the block but retains the block's subtree root contributions in the in-memory state.

When a chain fork occurs and pop_tip reverts the old tip, the winning fork's chain is extended. When that chain is later finalized, the stale subtree data from the reverted blocks is included in the RocksDB write batch and persisted to disk.

The pop_root/pop_tip asymmetry is specific to subtree root handling. Other state managed by pop_tip (nullifiers, UTXOs, anchors, block hashes) uses different cleanup patterns that are not affected.

Patches

zebra-state 7.0.0 and zebrad 4.5.0.

The fix adds subtree root cleanup to pop_tip matching the pattern already used by pop_root.

Workarounds

There is no configuration-level workaround. Chain forks are natural events on any Proof-of-Work network. Operators can mitigate the downstream impact by periodically verifying subtree root consistency using z_getsubtreesbyindex against a known-good reference.

Impact

Persistent corruption of Sapling and Orchard subtree root history in the RocksDB state database. The corruption survives node restarts. Downstream consumers that rely on z_getsubtreesbyindex for wallet synchronization (primarily lightwalletd and light wallets) receive incorrect subtree roots. This does not directly affect consensus validation of new blocks but can cause wallet synchronization failures or incorrect wallet state. Recovery requires rebuilding the state database from scratch.

Credit

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

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`zebra-state`	all versions	7.0.0`cargo update -p zebra-state --precise 7.0.0`
🦀crates.io	`zebrad`	all versions	4.5.0`cargo update -p zebrad --precise 4.5.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zebra-state, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zebra-state to 7.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52733 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Am I affected You are affected if: 1. You run `zebrad` up to and including `v4.4.1`. 2. Your node participates in a network where chain forks occur (mainnet, testnet, or any network with multiple miners). All default configurations are affected. The corruption persists across restarts because it is written to RocksDB. ### Summary When `pop_tip` removes the tip block during a chain fork, stale Sapling and Orchard note commitment subtree root data is retained in the in-memory non-finalized state. When the chain subsequently finalizes, this stale data is written to the persistent RocksDB