Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-77756

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
23/09/2026
Last modified:
23/09/2026

Description

Inconsistent Interpretation of HTTP Requests (&amp;#39;HTTP Request/Response Smuggling&amp;#39;) vulnerability in Apache Tomcat caused by processing the transfer-encoding header for an HTTP/1.0 request may allow an attacker to cause one request from another user to fail when Tomcat is located behind a reverse proxy.<br /> <br /> <br /> <br /> This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.47 through 9.0.121.<br /> <br /> <br /> <br /> The following versions were EOL at the time the CVE was created but are <br /> known to be affected: from 8.5.67 through 8.5.100. Other unsupported versions may also be affected.<br /> <br /> <br /> <br /> Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS v3.1 Severity and Metrics:

Base Score: 3.70 LOW
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): Low

Base Score 3.x
3.70
Severity 3.x
LOW

References to Advisories, Solutions, and Tools