CVE-2026-101356
Description
A flaw was found in Apache Tomcat. Incorrect object recycling and reuse during the HTTP/2 processing of asynchronous servlets can cause requests and responses to be mixed up between different users. A remote attacker could exploit this vulnerability to trigger unintended data cross-over, potentially leading to information disclosure.
Statement
A flaw was found in Apache Tomcat. When processing HTTP/2 requests using asynchronous servlets, improper object recycling and reuse can cause request and response data to be mixed up between concurrent client sessions. An unauthenticated remote attacker can exploit this condition by sending concurrent requests over HTTP/2, potentially receiving responses intended for other users and exposing sensitive application data processed within the Tomcat container context.
Mitigation
Disable the HTTP/2 UpgradeProtocol element in the Connector configuration within server.xml, or configure affected asynchronous servlets to use standard synchronous request handling.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
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