CVE-2017-5651

CVE-2017-5651 is a critical-severity vulnerability in Apache Tomcat with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In Apache Tomcat 9.0.0.M1 to 9.0.0.M18 and 8.5.0 to 8.5.12, the refactoring of the HTTP connectors introduced a regression in the send file processing. If the send file processing completed quickly, it was possible for the Processor to be added to the processor cache twice. This could result in the same Processor being used for multiple requests which in turn could lead to unexpected errors and/or response mix-up.

Frequently asked questions

What is CVE-2017-5651?
In Apache Tomcat 9.0.0.M1 to 9.0.0.M18 and 8.5.0 to 8.5.12, the refactoring of the HTTP connectors introduced a regression in the send file processing. If the send file processing completed quickly, it was possible for the Processor to be added to the processor cache twice. This could result in the same Processor being used for multiple requests which in turn could lead to unexpected errors and/or response mix-up.
How severe is CVE-2017-5651?
CVE-2017-5651 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-5651 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-2017-5651?
CVE-2017-5651 primarily affects Apache Tomcat. In total, 31 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-5651?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-5651 published?
CVE-2017-5651 was published on 2017-04-17 and last updated on 2026-06-17.

References

Affected products (31)

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