How severe is CVE-2026-28898?

CVE-2026-28898 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-28898 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-28898?

CVE-2026-28898 affects Apple Swiftnio Http/2. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-28898?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-28898 have an EU (EUVD) identifier?

Yes. CVE-2026-28898 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39533.

When was CVE-2026-28898 published?

CVE-2026-28898 was published on 2026-06-25 and last updated on 2026-06-30.

CVE-2026-28898

CVE-2026-28898 is a medium-severity vulnerability in Apple Swiftnio Http/2 with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-116.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39533
Weakness: CWE-116
Affected product: Apple Swiftnio Http/2
Published: 2026-06-25
Last modified: 2026-06-30

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.

Frequently asked questions

What is 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. 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.
How severe is CVE-2026-28898?: CVE-2026-28898 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-28898 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-28898?: CVE-2026-28898 affects Apple Swiftnio Http/2. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-28898?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-28898 have an EU (EUVD) identifier?: Yes. CVE-2026-28898 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39533.
When was CVE-2026-28898 published?: CVE-2026-28898 was published on 2026-06-25 and last updated on 2026-06-30.

References

https://github.com/advisories/GHSA-4px2-pw77-vc85

Affected products (1)

cpe:2.3:a:apple:swiftnio_http\/2:*:*:*:*:*:swift:*:*

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