CVE-2026-34481
Description
A flaw was found in Apache Log4j's JsonTemplateLayout. This vulnerability allows a remote attacker to disrupt log processing systems. By sending log events that include specific non-numeric floating-point values, the attacker can cause the JsonTemplateLayout to generate invalid JSON output. This invalid output can then lead to downstream systems rejecting or failing to index these logs, effectively causing a denial of service for log analysis.
Statement
Exploitation of this flaw requires an application to be configured with JsonTemplateLayout and to log attacker-controlled non-finite floating-point values within a MapMessage, which is not a default or common configuration in Red Hat products.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 6.5 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | Low | High | N/A |
| Availability Impact | Low | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Varies by Context; Unexpected State
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