Bug 2445449 (CVE-2026-24281)

Summary: CVE-2026-24281 Apache ZooKeeper: Apache ZooKeeper: Impersonation of servers or clients via reverse DNS spoofing
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: asoldano, ataylor, bbaranow, bmaxwell, brian.stansberry, caswilli, ccranfor, chfoley, darran.lofthouse, dbruscin, dosoudil, fjuma, fmariani, gmalinko, istudens, ivassile, iweiss, janstey, jkoehler, jpechane, kaycoth, kvanderr, lphiri, mosmerov, msvehla, nwallace, pberan, pdelbell, pesilva, pjindal, pmackay, rgodfrey, rstancel, rstepani, smaestri, swoodman, tcunning, tom.jenkinson, yfang
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-03-07 09:01:20 UTC
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.