How severe is CVE-2026-6328?

CVE-2026-6328 has a CVSS 4.0 base score of 8.3, rated high severity.

Is CVE-2026-6328 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-6328?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-6328 have an EU (EUVD) identifier?

Yes. CVE-2026-6328 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22832.

When was CVE-2026-6328 published?

CVE-2026-6328 was published on 2026-04-15 and last updated on 2026-06-17.

CVE-2026-6328

CVE-2026-6328 is a high-severity vulnerability with a CVSS 4.0 base score of 8.3. 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-20.

Key facts

Severity: High (CVSS 4.0 base score 8.3)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-22832
Weakness: CWE-20
Published: 2026-04-15
Last modified: 2026-06-17

Description

Improper input validation, Improper verification of cryptographic signature vulnerability in XQUIC Project XQUIC xquic on Linux (QUIC protocol implementation, packet processing module, STREAM frame handler modules) allows Protocol Manipulation.This issue affects XQUIC: through 1.8.3.

Frequently asked questions

What is CVE-2026-6328?: Improper input validation, Improper verification of cryptographic signature vulnerability in XQUIC Project XQUIC xquic on Linux (QUIC protocol implementation, packet processing module, STREAM frame handler modules) allows Protocol Manipulation.This issue affects XQUIC: through 1.8.3.
How severe is CVE-2026-6328?: CVE-2026-6328 has a CVSS 4.0 base score of 8.3, rated high severity.
Is CVE-2026-6328 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-6328?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-6328 have an EU (EUVD) identifier?: Yes. CVE-2026-6328 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22832.
When was CVE-2026-6328 published?: CVE-2026-6328 was published on 2026-04-15 and last updated on 2026-06-17.

References

https://github.com/alibaba/xquic/commit/4764604a0e487eeb49338b4498aecda2194eae84

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