Bug#1130496: zookeeper: CVE-2026-24281

[Salvatore Bonaccorso]

Source: zookeeper
Version: 3.9.4-2
Severity: important
Tags: security upstream
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for zookeeper.

CVE-2026-24281[0]:
| 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.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-24281
    https://www.cve.org/CVERecord?id=CVE-2026-24281
[1] https://lists.apache.org/thread/088ddsbrzhd5lxzbqf5n24yg0mwh9jt2

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore