RUSTSEC-2026-0262 `append-only-vec` 0.1.9 was removed from crates.io due to a malicious dependency
A malicious dependency in the append-only-vec crate allowed arbitrary code execution during build, requiring users to upgrade to a safe version.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is RUSTSEC-2026-0262?
RUSTSEC-2026-0262 is a vulnerability in append-only-vec, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A new version of the append-only-vec crate was published with a direct dependency
on proc-macro1, which would execute a malicious build script.
The compromised version of this crate was published on 2026-08-20, and was removed approximately 107 minutes later.
The compromised crate version was used as part of a malware campaign targeted
at users of arrayref, which was downloaded 2,285 times before being removed;
see the arrayref advisory for more detail.
Which versions are affected by RUSTSEC-2026-0262?
1 open source package ship an affected version, including append-only-vec.
| Package | Affected | Fixed in |
|---|---|---|
append-only-vec crates.io | From 0.1.9 | 0.1.10-0 |
How do I fix RUSTSEC-2026-0262?
Upgrade append-only-vec to 0.1.10-0 or later.
Is RUSTSEC-2026-0262 being exploited?
There is no known exploitation of RUSTSEC-2026-0262 in the wild and no public exploit code.