# CVE-2026-102360: lib0 `readUint8Array` performs an unbounded read past the end of the decoder’s view, disclosing adjacent process memory

> Remote attackers can read adjacent process memory via unbounded reads in lib0, exposing sensitive data like tokens and documents.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Sep 2026
- **Updated:** 29 Sep 2026
- **Also known as:** GHSA-r5c8-rf4w-qrq8

## What is CVE-2026-102360?

CVE-2026-102360 is a high-severity vulnerability in dmonad lib0, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A missing bounds check in the binary decoder in lib0, versions 0.2.1-0.2.117 and earlier and 1.0.0-rc.32 and earlier, lets any unauthenticated remote peer read adjacent process memory and receive it back. `readUint8Array` never compares the wire-supplied length against the decoder's own view, so one over-long length prefix returns whatever the host process allocated next: other tenants' document content, personal data, and live bearer session tokens**, recovered in full and at will. An attacker who can supply bytes to a lib0 decoder which means any peer that can open a socket, including before authentication reads adjacent process memory and, where the consumer echoes, stores or re-serves the decoded value, receives it back. This is patched in version 0.2.118 and 1.0.0-rc.33.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-102360?


## How do I fix CVE-2026-102360?

No fix has been published for CVE-2026-102360 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102360 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-102360 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102360 and fix it if it is affected.

What it is: CVE-2026-102360 is a high-severity vulnerability in dmonad lib0, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-102360 exists.

Affected product: dmonad lib0. 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-2026-102360/ (Markdown: https://insights.sbomify.com/CVE-2026-102360/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102360
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102360
- OSV: https://osv.dev/vulnerability/CVE-2026-102360

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102360/
Summaries are generated and may contain mistakes; the official description above is the record.