# RUSTSEC-2026-0234: Insufficient archive validation can cause out-of-bounds reads in archives containing hash tables

> Attackers can cause out-of-bounds reads or crashes by providing crafted archives to applications using the rkyv library.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 May 2026

## What is RUSTSEC-2026-0234?

RUSTSEC-2026-0234 is a memory corruption vulnerability in rkyv, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The archive validator could accept certain malformed relative pointers and
invalid `ArchivedHashTable` states. In particular, the hash table verifier did
not ensure that the number of occupied buckets matched the table's declared
length.

A crafted archive could pass the checks performed by the safe `rkyv::access`
and `rkyv::from_bytes` APIs and then cause an out-of-bounds read in later
validation, lookup, or deserialization. Depending on the input, this could
perform scalar or SIMD reads outside the archive buffer or crash the process.

Version 0.8.17 strengthens archive range validation and rejects hash tables
whose number of occupied buckets does not match their declared length. Users
who process untrusted archives should upgrade to 0.8.17 or later.

## Which versions are affected by RUSTSEC-2026-0234?

1 open source package ship an affected version, including rkyv.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rkyv` | crates.io | From 0.8.0-rc.1 | 0.8.17 |

## How do I fix RUSTSEC-2026-0234?

Upgrade rkyv to 0.8.17 or later.

## Is RUSTSEC-2026-0234 being exploited?

There is no known exploitation of RUSTSEC-2026-0234 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for RUSTSEC-2026-0234 and fix it if it is affected.

What it is: RUSTSEC-2026-0234 is a memory corruption vulnerability in rkyv, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of RUSTSEC-2026-0234 in the wild and no public exploit code.

Affected packages and fixed versions:
- rkyv (crates.io): affected from 0.8.0-rc.1; fixed in 0.8.17

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/RUSTSEC-2026-0234/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0234/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0234

---
From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0234/
Summaries are generated and may contain mistakes; the official description above is the record.