What is the CVSS score of CVE-2026-24281?

CVE-2026-24281 has a CVSS 3.1 base score of 7.4 (High). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2026-24281?

Yes, a public proof-of-concept exploit is available for CVE-2026-24281. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-24281?

Within 24 hours: Inventory all ZooKeeper instances and document network exposure; assess whether PTR records are controlled by trusted infrastructure. Within 7 days: Implement network segmentation to restrict ZooKeeper communication to trusted internal networks only; disable reverse DNS lookups in ZooKeeper configuration if possible. Within 30 days: Monitor vendor advisories for patch availability; evaluate migration to alternative distributed coordination systems or request vendor timeline for fix; implement enhanced monitoring for suspicious certificate validation or DNS anomalies.

Zookeeper CVE-2026-24281

HIGH

Improper Certificate Validation (CWE-295)

2026-03-07 security@apache.org

GHSA-7xrh-hqfc-g7qr

Apache Information Disclosure Zookeeper

7.4

CVSS 3.1 · NVD

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Control or spoof PTR DNS records
Exploit

Present trusted certificate matching PTR name
Execution

ZKTrustManager fails IP SAN validation and falls back to PTR
Impact

Impersonate ZooKeeper server or client

Vulnerability Assessment

Weakness	CWE CWE-295 OWASP Top 10:2025 A07:2025 - Authentication Failures ASVS 5.0 V12 - Secure Communication Certificate validation
Exploitation Conditions	ZooKeeper versions before 3.8.6 or 3.9.5 with default hostname verification enabled in client or quorum protocols. Attacker must possess a certificate trusted by ZKTrustManager and the target environment must resolve hostnames via reverse DNS (PTR) lookups during TLS handshakes.
Impact	CVSS 7.4 (HIGH). Attack vector: Network. Complexity: High. Privileges required: None. User interaction: None.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Hostname verification bypass in Apache ZooKeeper's ZKTrustManager allows attackers with a valid certificate trusted by the server to impersonate ZooKeeper nodes by exploiting fallback to reverse DNS validation when IP SAN checks fail. An attacker controlling or spoofing PTR records can intercept and forge communications between ZooKeeper servers and clients, compromising confidentiality and integrity of the cluster. No patch is currently available; mitigation requires upgrading to ZooKeeper 3.8.6 or 3.9.5 or disabling reverse DNS lookup via configuration.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:55 CVSS 7.4

RemediationAI

Update to version 3.8.6 or later. Restrict network access to the affected service where possible.

Affected Packages

maven org.apache.zookeeper:zookeeper fix: 3.8.6, 3.9.5

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in maven

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-295 (Improper Certificate Validation). Affects Zookeeper. Hostname verification in Apache ZooKeeper ZKTrustManager falls back to reverse DNS (PTR) when IP SAN validation fails, allowing attackers who control or spoof PTR records to impersonate ZooKeeper servers or clients with a valid certificate for the PTR name. It's important to note that attacker must present a certificate which is trusted by ZKTrustManager which makes the attack vector harder to exploit. Users are recommended to upgrade to version 3.8.6 or 3.9.5, which fixes this issue by introduc

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.4 HIGH

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Red Hat 7.4 MEDIUM

Primary rating from NVD.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

CVE Published

Mar 07, 2026 - 09:16 nvd

HIGH 7.4

DescriptionNVD

Hostname verification in Apache ZooKeeper ZKTrustManager falls back to reverse DNS (PTR) when IP SAN validation fails, allowing attackers who control or spoof PTR records to impersonate ZooKeeper servers or clients with a valid certificate for the PTR name. It's important to note that attacker must present a certificate which is trusted by ZKTrustManager which makes the attack vector harder to exploit. Users are recommended to upgrade to version 3.8.6 or 3.9.5, which fixes this issue by introducing a new configuration option to disable reverse DNS lookup in client and quorum protocols.

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

462 maven packages depend on org.apache.zookeeper:zookeeper (91 direct, 372 indirect)

Ecosystem-wide dependent count for version 3.8.0.

Executive ViewAI

Why It Matters

Apache ZooKeeper deployments are vulnerable to server impersonation attacks through DNS spoofing, potentially allowing attackers to intercept or manipulate cluster communications and compromise data integrity. This affects any organization using ZooKeeper for distributed coordination, configuration management, or service discovery, with no patch currently available to remediate the issue.

Business Impact: High

Compensating Controls

Restrict ZooKeeper network access to internal-only communication using firewalls and network segmentation; disable or restrict reverse DNS (PTR) lookups in ZooKeeper configuration; implement DNS security controls (DNSSEC) to prevent spoofing; enforce mutual TLS with certificate pinning where possible; deploy network monitoring to detect anomalous DNS queries or certificate usage; maintain strict access controls on DNS infrastructure to prevent PTR record modifications.

Threat Intelligence Overview

EPSS Score

0.0%

Top 95% exploitable

Exploit

POC

Public exploit code exists

Data Quality

6 sources

Confidence: High

NVD

CVE.org

EPSS Vendor

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +37

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.