# CVE-2026-11586: WS Auto-PONG memory exhaustion

> A malicious server can exhaust client memory by flooding curl with WebSocket PING frames, causing a denial of service.

- **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:** Yes
- **Published:** 3 Jul 2026
- **Updated:** 15 Sep 2026
- **Also known as:** ALPINE-CVE-2026-11586, BELL-CVE-2026-11586, CURL-CVE-2026-11586, DEBIAN-CVE-2026-11586, ECHO-2414-0950-1cdc, GHSA-c68q-h477-5646, JLSEC-2026-1200, MINI-2765-8hmm-vcr9, MINI-54wv-mw9v-r7fg, UBUNTU-CVE-2026-11586

## What is CVE-2026-11586?

CVE-2026-11586 is a high-severity denial of service vulnerability in Haxx Curl, published on 3 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

By default, curl automatically responds to WebSocket PING frames. Because curl
lacks an upper bound on memory allocation for unacknowledged frames, a
malicious server can exhaust all available memory by flooding curl with rapid,
sequential PING messages.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-11586?

It affects 1 product.


Products: Haxx Curl.

## How do I fix CVE-2026-11586?

Apply the vendor's patch.

## Is CVE-2026-11586 being exploited?

There is no known exploitation of CVE-2026-11586 in the wild and no public exploit code.

## Other vulnerabilities in Haxx Curl

- [CVE-2026-19931](https://insights.sbomify.com/CVE-2026-19931/): Negotiate ambient user conn reuse (critical 9.8)
- [CVE-2026-10536](https://insights.sbomify.com/CVE-2026-10536/): HTTP/2 stream-dependency tree UAF (critical 9.8)
- [CVE-2026-11856](https://insights.sbomify.com/CVE-2026-11856/): cross-origin Digest auth state leak (critical 9.8)
- [CVE-2026-8925](https://insights.sbomify.com/CVE-2026-8925/): SASL double-free (critical 9.8)
- [CVE-2026-9079](https://insights.sbomify.com/CVE-2026-9079/): stale proxy password leak (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11586 and fix it if it is affected.

What it is: CVE-2026-11586 is a high-severity denial of service vulnerability in Haxx Curl, published on 3 Jul 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 CVE-2026-11586 in the wild and no public exploit code.

Affected product: Haxx Curl. 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-2026-11586/ (Markdown: https://insights.sbomify.com/CVE-2026-11586/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11586
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11586
- OSV: https://osv.dev/vulnerability/CVE-2026-11586

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11586/
Summaries are generated and may contain mistakes; the official description above is the record.