CVE-2026-46690 unbounded-spsc: Sender::send pointer-as-value transmute causes OOB read and fake-Arc drop under TX/RX race
A race condition in the unbounded-spsc Rust library allows out-of-bounds reads and memory corruption via pointer transmutation, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-46690?
CVE-2026-46690 is a medium-severity vulnerability in spearman unbounded-spsc, published on 12 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
unbounded_spsc is an "unbounded" extension of bounded_spsc_queue. In versions 0.2.0 and prior, sender::send pointer-as-value transmute causes OOB read and fake-Arc drop under TX/RX race. At time of publication, there are no publicly available patches.
Which versions are affected by CVE-2026-46690?
2 open source packages ship an affected version, including unbounded-spsc. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
unbounded-spsc crates.io | All versions to 0.2.0 | None |
unbounded-spsc crates.io | All versions to 0.2.0 | None |
Products include Spearman Unbounded-Spsc.
How do I fix CVE-2026-46690?
No fix has been published for CVE-2026-46690 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-46690 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46690 exists.
Sources
Also known as GHSA-6m57-8r3p-pqx6.