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<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>VulnFeed.org: Apache Software Foundation Apache ZooKeeper</title><link>https://vulnfeed.org/</link><description>Every disclosure, as it lands. Critical-only feed available.</description><language>en</language><atom:link href="https://vulnfeed.org/feed/product/apache-software-foundation-apache-zookeeper.xml" rel="self" type="application/rss+xml"/><item><title>CVE-2026-115448: Apache ZooKeeper: Unbounded recursion in snapshot serialization allows a client to render the server unrecoverable</title><link>https://vulnfeed.org/cve/CVE-2026-115448/</link><guid isPermaLink="true">https://vulnfeed.org/cve/CVE-2026-115448/</guid><pubDate>Wed, 04 Nov 2026 11:17:14 +0000</pubDate><description>Uncontrolled recursion in Apache ZooKeeper. The server serializes its data tree to a snapshot by recursing one stack frame per znode level, with no depth bound. A client permitted to create znodes (the default root ACL is open) can build a chain of nested znodes deep enough that taking a snapshot exhausts the JVM stack and kills the snapshot thread; sizes stay within jute.maxbuffer, so existing limits do not prevent it. This is a denial of service that becomes persistent: on restart the server rebuilds the deep tree from its transaction log and fails again while taking the startup snapshot, so it does not return to service, and recovery can entail data loss. The same log affects a leader and its followers, so it can spread across an ensemble. This issue affects Apache ZooKeeper 3.8.0 through 3.8.7 and 3.9.0 through 3.9.6. Users are recommended to upgrade to 3.8.8 or 3.9.7, which fix the issue. As a workaround, use ACLs and authentication to restrict znode creation rather than relying on the default open root ACL.</description></item><item><title>CVE-2026-100252: Apache ZooKeeper: SASL authorization bypass on the client port through a client-supplied authorization ID</title><link>https://vulnfeed.org/cve/CVE-2026-100252/</link><guid isPermaLink="true">https://vulnfeed.org/cve/CVE-2026-100252/</guid><pubDate>Wed, 04 Nov 2026 11:17:06 +0000</pubDate><description>Improper Authorization vulnerability in Apache ZooKeeper. When SASL authentication is enabled on the client port, the server&apos;s SASL callback handler grants every authorization identity (authzid) that a client requests, without checking it against the principal the client authenticated as. The server then tries to replace the requested identity with a canonical form of the authenticated principal, derived from the zookeeper.security.auth_to_local rules. If no rule applies to the principal, canonicalization fails and the error is only logged. The client-requested authzid then becomes the session&apos;s SASL identity for all ACL checks. An authenticated client whose principal is not covered by the auth_to_local rules can therefore claim any SASL identity. With the default rules, this includes any Kerberos principal from a realm other than the server&apos;s default realm, such as a principal from a cross-realm trusted realm. The client then gets the permissions granted to that identity in sasl ACLs. If the requested identity matches a configured zookeeper.superUser, it gets superuser access to the whole data tree. Users are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.</description></item><item><title>CVE-2026-100300: Apache ZooKeeper: Unauthenticated persistent denial of service via unvalidated quota-node data and paths crashing the transaction-apply thread</title><link>https://vulnfeed.org/cve/CVE-2026-100300/</link><guid isPermaLink="true">https://vulnfeed.org/cve/CVE-2026-100300/</guid><pubDate>Wed, 04 Nov 2026 11:17:06 +0000</pubDate><description>Improper handling of exceptional conditions in the quota subsystem of Apache ZooKeeper allows an attacker able to write under the /zookeeper/quota subtree — unauthenticated on default deployments, where that subtree is world-writable — to crash the server&apos;s critical request-processing thread and render the on-disk data directory permanently unbootable. This issue affects Apache ZooKeeper up to and including 3.9.6. Users are recommended to upgrade to version 3.8.8 or 3.9.7, which fixes the issue.</description></item><item><title>CVE-2026-100302: Apache ZooKeeper: Denial of service through unbounded memory allocation in multiRead request handling</title><link>https://vulnfeed.org/cve/CVE-2026-100302/</link><guid isPermaLink="true">https://vulnfeed.org/cve/CVE-2026-100302/</guid><pubDate>Wed, 04 Nov 2026 10:46:20 +0000</pubDate><description>Allocation of Resources Without Limits or Throttling in the multiRead request handler of Apache ZooKeeper allows a remote attacker to crash the server (denial of service) with a single small request. The multiRead handler places no limit on the number of bundled read operations or on the cumulative size of the response it builds in memory. Because each operation&apos;s result is fully materialized and retained before serialization, a request that is small on the wire — within the jute.maxbuffer limit — but that references a large znode many times can force the server to allocate far more heap than the request size implies, exhausting the JVM heap and terminating the server with an OutOfMemoryError. Neither jute.maxbuffer nor largeRequestMaxBytes prevents this, as both bound only the inbound request, not the response. This issue affects Apache ZooKeeper from 3.7.0 through 3.9.6. Users are recommended to upgrade to version 3.9.7, which enforces configurable limits on the multiRead operation count and cumulative response size.</description></item></channel></rss>
