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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00181.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Apple swift-nio-http2 affected
Version Status Constraints
0 affected < 1.45.0

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Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-q3g2-m552-3r9c swift-nio-http2: Missing CR/LF/NUL validation in header values
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/apple/swift-nio-http2/security/advisories/GHSA-q3g2-m552-3r9c cve-icon
History

Sun, 26 Jul 2026 04:45:00 +0000

Type Values Removed Values Added
Title Missing Validation on HTTP/2 HEADERS Enables Request Smuggling

Fri, 24 Jul 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-444
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 23 Jul 2026 21:45:00 +0000

Type Values Removed Values Added
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.
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: apple

Published:

Updated: 2026-07-24T20:06:58.518Z

Reserved: 2026-07-20T18:11:03.398Z

Link: CVE-2026-64785

cve-icon Vulnrichment

Updated: 2026-07-24T20:05:52.056Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-26T04:30:05Z

Weaknesses