RUSTSEC-2026-0235 Insufficient archive validation can cause out-of-bounds reads in archives containing Rc/Arc
Attackers can craft malicious archives to trigger out-of-bounds reads via forged slice lengths in rkyv, potentially leaking memory or crashing applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is RUSTSEC-2026-0235?
RUSTSEC-2026-0235 is a memory corruption vulnerability in rkyv, published on 13 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Shared pointer validation keyed already-validated pointees by their address and
type, but did not include pointer metadata. For unsized pointees, an archive
could therefore contain multiple Rc, Arc, or weak pointers that shared a
data address but used different metadata, such as different slice lengths.
Once the first pointer had been validated, later pointers to the same address
skipped pointee validation. The safe checked rkyv::access API could
consequently return a slice with a forged length, allowing safe indexing to
read out of bounds. The same validation bypass was reachable through checked
deserialization with rkyv::from_bytes.
Version 0.8.17 includes pointer metadata in shared pointer validation and rejects conflicting metadata. The 0.7 series is also affected but is no longer supported by upstream. Users who process untrusted archives should upgrade to 0.8.17 or later.
Which versions are affected by RUSTSEC-2026-0235?
1 open source package ship an affected version, including rkyv.
| Package | Affected | Fixed in |
|---|---|---|
rkyv crates.io | From 0.7.0-pre.2 | 0.8.17 |
How do I fix RUSTSEC-2026-0235?
Upgrade rkyv to 0.8.17 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is RUSTSEC-2026-0235 being exploited?
There is no known exploitation of RUSTSEC-2026-0235 in the wild and no public exploit code.