# CVE-2026-86227: valkey-io valkey kvstore.c kvstoreGetHashtable out-of-bounds

> Remote attackers can cause denial of service via out-of-bounds read in Valkey cluster mode if they control the startup RDB file.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Sep 2026
- **Updated:** 9 Sep 2026
- **Also known as:** BELL-CVE-2026-86227, DEBIAN-CVE-2026-86227, GHSA-74wm-q835-hxf9, UBUNTU-CVE-2026-86227

## What is CVE-2026-86227?

CVE-2026-86227 is a low-severity memory corruption vulnerability in valkey-io valkey, published on 6 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A weakness has been identified in valkey-io valkey up to 9.0.5/9.1.1. This affects the function kvstoreGetHashtable of the file src/kvstore.c. This manipulation of the argument didx causes out-of-bounds read. It is possible to initiate the attack remotely. The attack is considered to have high complexity. It is indicated that the exploitability is difficult. The exploit has been made available to the public and could be used for attacks. Patch name: 4691888e7fab3df128f0bde5750c9fde2ae552fa. To fix this issue, it is recommended to deploy a patch. Exploitation requires cluster mode plus attacker-controlled dump.rdb at startup (data-dir write access, replication feed, or a stored crafted RDB) - an attacker-position DoS at boot, not network pre-auth. The issue report was closed stating it "is worth fixing for the sake of memory safety… but I don't think it meets our bar for a security disclosure."

Weakness: CWE-125 (Out-of-bounds Read), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-86227?


## How do I fix CVE-2026-86227?

Apply the vendor's patch.

## Is CVE-2026-86227 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86227 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86227 and fix it if it is affected.

What it is: CVE-2026-86227 is a low-severity memory corruption vulnerability in valkey-io valkey, published on 6 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86227 exists.

Affected product: valkey-io valkey. No package-level version data is available, so check the vendor advisory linked from the reference page.

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/CVE-2026-86227/ (Markdown: https://insights.sbomify.com/CVE-2026-86227/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86227
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86227
- OSV: https://osv.dev/vulnerability/CVE-2026-86227

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-86227/
Summaries are generated and may contain mistakes; the official description above is the record.