Medium severity · published Jun 25, 2026
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
5.3
CVSS
0.3%
EPSS
No
On KEV
Description
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. swift-nio-http2 1.44.1 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :status) at both the HPACK header validation layer and the HTTP/2-to-HTTP/1.1 translation layer. Requests or responses containing CR, LF, or NUL bytes in any pseudo-header value are now rejected with a connection error. This issue is fixed in swift-nio-http2 1.44.1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% 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 1.44.1 · source: vendor
SH
Swiftnio Http/2 · Apple
before 1.44.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28898
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-28898
Third Party Advisory
https://github.com/advisories/GHSA-4px2-pw77-vc85
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