How severe is CVE-2026-24281?

CVE-2026-24281 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-24281 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-24281?

CVE-2026-24281 affects Apache Zookeeper. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-24281?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-24281 have an EU (EUVD) identifier?

Yes. CVE-2026-24281 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10139.

When was CVE-2026-24281 published?

CVE-2026-24281 was published on 2026-03-07 and last updated on 2026-07-03.

CVE-2026-24281

CVE-2026-24281 is a high-severity vulnerability in Apache Zookeeper with a CVSS 3.x base score of 7.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: High (CVSS 3.x base score 7.4)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10139
Weakness: CWE-295
Affected product: Apache Zookeeper
Published: 2026-03-07
Last modified: 2026-07-03

Description

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.

Frequently asked questions

What is CVE-2026-24281?: 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.
How severe is CVE-2026-24281?: CVE-2026-24281 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-24281 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-24281?: CVE-2026-24281 affects Apache Zookeeper. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-24281?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-24281 have an EU (EUVD) identifier?: Yes. CVE-2026-24281 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10139.
When was CVE-2026-24281 published?: CVE-2026-24281 was published on 2026-03-07 and last updated on 2026-07-03.

References

Affected products (1)

cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*

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