# CVE-2026-77384: libp2p: Circuit relay v2 server reservation refresh leaks abort listeners and allows remote resource exhaustion

> Remote peers can cause denial of service in libp2p circuit relay servers by triggering unbounded memory growth through repeated reservation requests.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** GHSA-x787-gh7p-hmq7

## What is CVE-2026-77384?

CVE-2026-77384 is a high-severity denial of service vulnerability in js-libp2p, published on 24 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libp2p is a JavaScript implementation of the libp2p networking stack. Prior to version 4.2.9, the reservation refresh path in reservation-store.ts reuses the same retimeableSignal but unconditionally registers another abort listener on every refresh. As a result, a remote peer can repeatedly send valid RESERVE requests for the same reservation, causing unbounded listener and closure growth in @libp2p/circuit-relay-v2 relay servers and leading to denial of service. This issue is fixed in version 4.2.9.

Weakness: CWE-772 (Missing Release of Resource after Effective Lifetime), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-77384?


## How do I fix CVE-2026-77384?

No fix has been published for CVE-2026-77384 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77384 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77384 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77384 and fix it if it is affected.

What it is: CVE-2026-77384 is a high-severity denial of service vulnerability in js-libp2p, published on 24 Aug 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-2026-77384 exists.

Affected product: js-libp2p. 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-2026-77384/ (Markdown: https://insights.sbomify.com/CVE-2026-77384/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77384
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77384
- OSV: https://osv.dev/vulnerability/CVE-2026-77384

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77384/
Summaries are generated and may contain mistakes; the official description above is the record.