CVE-2019-16869

CVE-2019-16869 is a high-severity vulnerability in Netty with a CVSS 3.x base score of 7.5. 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

Description

Netty before 4.1.42.Final mishandles whitespace before the colon in HTTP headers (such as a "Transfer-Encoding : chunked" line), which leads to HTTP request smuggling.

Frequently asked questions

What is CVE-2019-16869?
Netty before 4.1.42.Final mishandles whitespace before the colon in HTTP headers (such as a "Transfer-Encoding : chunked" line), which leads to HTTP request smuggling.
How severe is CVE-2019-16869?
CVE-2019-16869 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2019-16869 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-16869?
CVE-2019-16869 primarily affects Netty. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-16869?
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.
When was CVE-2019-16869 published?
CVE-2019-16869 was published on 2019-09-26 and last updated on 2026-06-17.

References

Affected products (8)

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