How severe is CVE-2026-42585?

CVE-2026-42585 has a CVSS 3.x base score of 6.5, 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 low, and availability none.

Is CVE-2026-42585 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42585?

CVE-2026-42585 affects Netty. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42585?

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

Does CVE-2026-42585 have an EU (EUVD) identifier?

Yes. CVE-2026-42585 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30128.

When was CVE-2026-42585 published?

CVE-2026-42585 was published on 2026-05-13 and last updated on 2026-06-17.

CVE-2026-42585

CVE-2026-42585 is a medium-severity vulnerability in Netty with a CVSS 3.x base score of 6.5. 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-444.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30128
Weakness: CWE-444
Affected product: Netty
Published: 2026-05-13
Last modified: 2026-06-17

Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

Frequently asked questions

What is CVE-2026-42585?: Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
How severe is CVE-2026-42585?: CVE-2026-42585 has a CVSS 3.x base score of 6.5, 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 low, and availability none.
Is CVE-2026-42585 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42585?: CVE-2026-42585 affects Netty. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42585?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-42585 have an EU (EUVD) identifier?: Yes. CVE-2026-42585 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30128.
When was CVE-2026-42585 published?: CVE-2026-42585 was published on 2026-05-13 and last updated on 2026-06-17.

References

https://github.com/netty/netty/security/advisories/GHSA-38f8-5428-x5cv

Affected products (1)

cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

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