Medium severity · published Jul 23, 2026
CVE-2026-64785
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…
5.3
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SW
swift-nio-http2 · Apple
before 1.45.0 · source: vendor
SH
Swiftnio Http/2 · Apple
before 1.45.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64785
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-64785
Vendor Advisory
https://github.com/apple/swift-nio-http2/security/advisories/GHSA-q3g2-m552-3r9c
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5.3
CVE-2026-28898
swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message