CVE-2024-23944

A missing ACL check in the persistent watchers handling of Apache ZooKeeper allows an attacker to monitor child znodes. By attaching a persistent watcher (via the addWatch command) to a parent znode they already have access to, an attacker can observe the full path of znodes that trigger watch ev...

CVE-2023-44981

CVE-2023-44981 (Apache ZooKeeper) : Authorization bypass through a user-controlled SASL ID when quorum peer authentication is enabled (quorum.auth.enableSasl=true). If the instance part of the SASL ID is missing (e.g., [email protected]), authorization checks are skipped, allowing an arbitrary endp...

CVE-2021-21295

Netty CVE-2021-21295 affects io.netty:netty-codec-http2 prior to 4.1.60.Final, where Content-Length validation can be bypassed when HTTP/2 is downgraded to HTTP/1.1 in proxied scenarios, enabling HTTP request smuggling. The issue occurs when HTTP2MultiplexCodec/Http2FrameCodec are used and Http2S...

CVE-2019-0201

CVE-2019-0201 affects Apache ZooKeeper up to versions 3.4.13 and 3.5.4-beta, where getACL() does not enforce permissions and returns the ACL Id in plaintext. When Digest Authentication is in use, the unsalted hash value contained in the Id field can be disclosed to unauthenticated or unprivileged...

CVE-2024-51504

The ZooKeeper Admin Server is vulnerable to an Authentication Bypass by Spoofing (CWE-290) due to a weak default configuration in the IPAuthenticationProvider . Specifically, the provider honors the X-Forwarded-For HTTP request header, which can be easily spoofed by an attacker to bypass IP-based...

CVE-2026-24308

CVE-2026-24308 affects Apache ZooKeeper: improper handling of configuration values in ZKConfig can expose sensitive client configuration in logs at INFO level. Affected: ZooKeeper 3.8.5 and 3.9.4 on all platforms. Impact: potential leakage of sensitive config data in production logs. Mitigation: ...

CVE-2017-5637

CVE-2017-5637 affects Apache ZooKeeper prior to fixes in 3.4.10 and 3.5.3. The issue: two four-letter commands, wchp and wchc, are CPU-intensive and can cause a denial of service by overwhelming CPU on the server, rendering it unable to serve legitimate clients. Affected products/versions include...

CVE-2018-8012

CVE-2018-8012 affects Apache ZooKeeper: no authentication/authorization is enforced when a server attempts to join a quorum (before 3.4.10 and 3.5.0-alpha to 3.5.3-beta). This allows an arbitrary endpoint to join the cluster and propagate counterfeit changes to the leader. IBM and related advisor...

CVE-2026-24281

CVE-2026-24281 — Apache ZooKeeper ZKTrustManager reverse DNS fallback . The vulnerability arises when IP SAN validation fails and ZKTrustManager falls back to PTR-based name resolution, enabling attackers who control or spoof PTR records to impersonate ZooKeeper servers or clients with certificat...

CVE-2016-5017

CVE-2016-5017 affects Apache ZooKeeper before 3.4.9 and 3.5.x before 3.5.3. The vulnerability is a buffer overflow in the C CLI shells (cli_st/cli_mt) caused by improper bounds checking when a long command string is used, potentially allowing arbitrary code execution. Remediation stated in the so...

CVE-2025-58457

Apache ZooKeeper (versions 3.9.0 before 3.9.4) contains an improper permission check in the AdminServer, allowing authorized clients to execute snapshot and restore commands with insufficient privileges (CWE-280). This vulnerability impacts several products, including IBM Sterling B2B Integrator ...

CVE-2026-59969

Apache ZooKeeper contains a vulnerability where quorum TLS fails to enforce peer hostname verification in FIPS-mode deployments. When specific settings are enabled—namely sslQuorum=true, zookeeper.fips-mode=true, ssl.quorum.hostnameVerification=true, and ssl.quorum.clientHostnameVerification=true...

CVE-2026-59739

Apache ZooKeeper is vulnerable to information disclosure due to a missing ACL check in the SetWatches reconnect replay handler. An attacker can discover ACL-restricted paths by registering exists-watches on non-existent paths and then reconnecting after those paths are created with restricted ACL...

CVE-2026-79993

Apache ZooKeeper versions 3.9.0 through 3.9.5 and 3.8.0 through 3.8.6 are vulnerable to an authorization bypass due to a missing ACL check on the deleteContainer opcode (0x14/20). While this opcode is intended for internal use and lacks an official client API, an attacker can open a plain TCP ses...

CVE-2026-84439

An unauthenticated attacker can perform a log injection attack on Apache ZooKeeper (versions 3.9.0 through 3.9.5 and 3.8.0 through 3.8.6 ) when audit logging is enabled (zookeeper.audit.enable=true). By sending a digest authentication request containing tab characters ( ) in the username, an atta...

CVE-2026-84501

An unauthenticated attacker can inject arbitrary fake log lines into Apache ZooKeeper 's operational log by sending a crafted add_auth("ensemble", ...) request containing newline characters (\n ). The vulnerability occurs because the EnsembleAuthenticationProvider.handleAuthentication() method lo...