CVE-2026-24281
Description
A flaw was found in Apache ZooKeeper. The ZKTrustManager component's hostname verification process can fall back to reverse DNS (PTR) lookup when IP Subject Alternative Name (SAN) validation fails. This vulnerability allows an attacker who can control or spoof PTR records to impersonate ZooKeeper servers or clients, provided they possess a valid certificate for the PTR name. This could lead to unauthorized access or manipulation of ZooKeeper services.
Mitigation
To mitigate this issue, disable reverse DNS lookup in Apache ZooKeeper's client and quorum protocols. This can be achieved by configuring the `zookeeper.ssl.hostnameVerification.disableReverseDns` property to `true`. This configuration option is available in Apache ZooKeeper versions 3.8.6 and 3.9.5 and later. A restart of the ZooKeeper service will be required for the change to take effect.
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 | 7.4 | 7.4 | 7.4 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Authentication
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host.
Frequently Asked Questions
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