# CVE-2026-64785: swift-nio-http2: Missing CR/LF/NUL validation in header values

> Attackers can smuggle HTTP requests or split responses by exploiting missing control character validation in SwiftNIO HTTP/2 headers.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Jul 2026
- **Updated:** 24 Jul 2026
- **Also known as:** GHSA-q3g2-m552-3r9c

## What is CVE-2026-64785?

CVE-2026-64785 is a medium-severity vulnerability in Apple swift-nio-http2, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let CR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend through NIOHTTP2's HTTP/2-to-HTTP/1 codec, enabling HTTP request smuggling or response splitting. This vulnerability is addressed in swift-nio-http2 version 1.45.0.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2026-64785?

2 open source packages ship an affected version, including swift-nio-http2. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `swift-nio-http2` | SwiftURL | All versions | 1.45.0 |
| `swift-nio-http2` | SwiftURL | All versions | 1.45.0 |

Products: Apple Swiftnio Http\/2.

## How do I fix CVE-2026-64785?

Upgrade swift-nio-http2 to 1.45.0 or later.

## Is CVE-2026-64785 being exploited?

There is no known exploitation of CVE-2026-64785 in the wild and no public exploit code.

## Other vulnerabilities in Apple swift-nio-http2

- [CVE-2022-0618](https://insights.sbomify.com/CVE-2022-0618/): Denial of service via HTTP/2 HEADERS frames padding (high 7.5)
- [CVE-2022-24666](https://insights.sbomify.com/CVE-2022-24666/): swift-nio-http2 vulnerable to denial of service via invalid HTTP/2 HEADERS frame length (high 7.5)
- [CVE-2022-24667](https://insights.sbomify.com/CVE-2022-24667/): swift-nio-http2 vulnerable to denial of service via mishandled HPACK variable length integer encoding (high 7.5)
- [CVE-2022-24668](https://insights.sbomify.com/CVE-2022-24668/): swift-nio-http2 vulnerable to denial of service via ALTSVC or ORIGIN frames (high 7.5)
- [CVE-2026-28898](https://insights.sbomify.com/CVE-2026-28898/): SwiftNIO HTTP/2: HTTP/2-to-HTTP/1 Request Smuggling via unvalidated :path pseudo-header in HTTP2ToHTTP1Codec (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-64785 and fix it if it is affected.

What it is: CVE-2026-64785 is a medium-severity vulnerability in Apple swift-nio-http2, published on 23 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-2026-64785 in the wild and no public exploit code.

Affected packages and fixed versions:
- swift-nio-http2 (SwiftURL): affected all versions; fixed in 1.45.0
- swift-nio-http2 (SwiftURL): affected all versions; fixed in 1.45.0

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-2026-64785/ (Markdown: https://insights.sbomify.com/CVE-2026-64785/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64785
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64785
- OSV: https://osv.dev/vulnerability/CVE-2026-64785

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64785/
Summaries are generated and may contain mistakes; the official description above is the record.