CVE-2026-55955
Description
A flaw was found in Apache Tomcat. An improper authentication vulnerability in the EncryptionInterceptor component allows a remote attacker to perform a replay attack. This could lead to unauthorized access or manipulation of data within the cluster component.
Statement
A flaw was found in Apache Tomcat's EncryptionInterceptor used for Tribes cluster communication. An improper authentication vulnerability allows a replay attack against encrypted cluster messages. Exploitation requires the EncryptionInterceptor to be configured for Tomcat clustering, which is a non-default configuration, and the attacker must have access to the cluster network to capture and replay messages. Apache rates this vulnerability as Low severity. Red Hat has corrected the impact from IMPORTANT to MODERATE — the original AI-Bot CVSS of 8.2 (AV:N/AC:L) incorrectly scored this as internet-facing with low complexity, when Tribes cluster traffic is adjacent-network (AV:A) and requires non-default clustering configuration (AC:H). The corrected vector is CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N (4.2).
Mitigation
This vulnerability only affects Tomcat deployments using the EncryptionInterceptor for Tribes cluster communication. Deployments that do not use Tomcat clustering or do not configure the EncryptionInterceptor are not affected. Ensure cluster communication channels are restricted to trusted, isolated networks.
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 | 4.2 | N/A | 6.5 |
| Attack Vector | Adjacent Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Gain Privileges or Assume Identity
Messages sent with a capture-relay attack allow access to resources which are not otherwise accessible without proper authentication.
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