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CVE-2026-77756 is an HTTP request/response smuggling vulnerability in Apache Tomcat. Tomcat processes the Transfer-Encoding header on HTTP/1.0 requests, which can produce inconsistent request interpretation between Tomcat and an upstream reverse proxy. This desynchronization can permit an attacker to interfere with request handling and cause a subsequent request from another user to fail. Affected versions are Tomcat 11.0.0-M1 through 11.0.25, 10.1.0-M1 through 10.1.59, and 9.0.47 through 9.0.121. Tomcat 8.5.67 through 8.5.100 is also known to be affected.
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A reverse-proxy request-interference vulnerability caused by honoring Transfer-Encoding in HTTP/1.0 traffic.
An Apache Tomcat request-disruption flaw involving Transfer-Encoding handling for HTTP/1.0 traffic behind a reverse proxy.
An HTTP request/response smuggling vulnerability in Apache Tomcat. Processing the Transfer-Encoding header in HTTP/1.0 requests can cause inconsistent request interpretation between Tomcat and a reverse proxy, allowing an attacker to make another user's request fail.
Unknown; the content lists this Apache Tomcat CVE but provides no technical description.
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Cross-references every affected SKU, including bundled OEM variants.
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