Quick answers
- Is CVE-2026-52732 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-52732 being exploited in the wild.
- How severe is CVE-2026-52732?
- Medium severity, with a CVSS score of 5.3, published 18 August 2026.
- Which products and versions are affected?
- zebrad (crates.io) <= 4.4.1, SEMVER:introduced=0,fixed=4.5.0; Zcash Foundation Zebra <= 4.4.1.
- Is there a fix for CVE-2026-52732?
- Yes. zebrad (crates.io): upgrade to 4.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-52732 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-52732?
- Check whether you run zebrad (crates.io) or Zcash Foundation Zebra at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- zebrad (crates.io): upgrade to 4.5.0 or later
cargo update -p zebrad
Technical details
The zebrad mempool download and verification pipeline (downloads.rs) uses a bounded pool of 25 concurrent tasks without per-peer accounting or throttling. An unauthenticated remote attacker can monopolize these slots by sending 'inv' messages with fake transaction IDs and then remaining silent, forcing the node to hold the slots until a 20-second timeout occurs. Because the inbound service maps queue-full errors to a null response, existing overload protection and peer disconnection logic are bypassed. The vulnerability is addressed in version 4.5.0 by implementing per-peer queue limits and improved misbehavior attribution.
Affected products
- ZcashFoundation zebrad <= 4.4.1
Identifiers
- CVE-2026-52732
- GHSA-4fc2-h7jh-287c
Timeline
- 2026-05-29: disclosed: Reported via private GitHub Security Advisory
- 2026-07-02: advisory: GitHub Advisory published