SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2016-8745

Sharing a Processor can result in information leakage between requests including, not not limited to, session ID and the response body.

HIGH 7.5EPSS 16.0%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 16.0%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

Description

A bug in the error handling of the send file code for the NIO HTTP connector in Apache Tomcat 9.0.0.M1 to 9.0.0.M13, 8.5.0 to 8.5.8, 8.0.0.RC1 to 8.0.39, 7.0.0 to 7.0.73 and 6.0.16 to 6.0.48 resulted in the current Processor object being added to the Processor cache multiple times. This in turn meant that the same Processor could be used for concurrent requests. Sharing a Processor can result in information leakage between requests including, not not limited to, session ID and the response body. The bug was first noticed in 8.5.x onwards where it appears the refactoring of the Connector code for 8.5.x onwards made it more likely that the bug was observed. Initially it was thought that the 8.5.x refactoring introduced the bug but further investigation has shown that the bug is present in all currently supported Tomcat versions.

CVSS 3.0
7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
16.04% probability · 97th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-388
Affected
apache/tomcat
Source
security@apache.org
EPSS trend
0%10%20%21 September 2026: 14.94%22 September 2026: 16.04%27 October 2026: 16.04%21 September 202627 October 2026

EPSS moved from 14.9% on 21 September 2026 to 16.0% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.