8.7 CVE-2026-35554
A race condition in the Apache Kafka Java producer client’s buffer pool management can cause messages to be silently delivered to incorrect topics.
When a produce batch expires due to delivery.timeout.ms while a network request containing that batch is still in flight, the batch’s ByteBuffer is prematurely deallocated and returned to the buffer pool. If a subsequent producer batch—potentially destined for a different topic—reuses this freed buffer before the original network request completes, the buffer contents may become corrupted. This can result in messages being delivered to unintended topics without any error being reported to the producer.
Data Confidentiality:
Messages intended for one topic may be delivered to a different topic, potentially exposing sensitive data to consumers who have access to the destination topic but not the intended source topic.
Data Integrity:
Consumers on the receiving topic may encounter unexpected or incompatible messages, leading to deserialization failures, processing errors, and corrupted downstream data.
This issue affects Apache Kafka versions ≤ 3.9.1, ≤ 4.0.1, and ≤ 4.1.1.
Kafka users are advised to upgrade to 3.9.2, 4.0.2, 4.1.2, 4.2.0, or later to address this vulnerability.
https://nvd.nist.gov/vuln/detail/CVE-2026-35554
Categories
CWE-362 : Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. Black box methods may be able to identify evidence of race conditions via methods such as multiple simultaneous connections, which may cause the software to become instable or crash. However, race conditions with very narrow timing windows would not be detectable. Common idioms are detectable in white box analysis, such as time-of-check-time-of-use (TOCTOU) file operations (CWE-367), or double-checked locking (CWE-609). In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance. Use thread-safe capabilities such as the data access abstraction in Spring. When using multithreading and operating on shared variables, only use thread-safe functions. Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write. Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412. Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization. Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop. Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help. Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations. Go application for cloud management creates a world-writable sudoers file that allows local attackers to inject sudo rules and escalate privileges to root by winning a race condition. Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV. Chain: mobile platform race condition (CWE-362) leading to use-after-free (CWE-416), as exploited in the wild per CISA KEV. Chain: race condition (CWE-362) leads to use-after-free (CWE-416), as exploited in the wild per CISA KEV. chain: JTAG interface is not disabled (CWE-1191) during ROM code execution, introducing a race condition (CWE-362) to extract encryption keys Chain: race condition (CWE-362) in anti-malware product allows deletion of files by creating a junction (CWE-1386) and using hard links during the time window in which a temporary file is created and deleted. TOCTOU in sandbox process allows installation of untrusted browser add-ons by replacing a file after it has been verified, but before it is executed Chain: chipset has a race condition (CWE-362) between when an interrupt handler detects an attempt to write-enable the BIOS (in violation of the lock bit), and when the handler resets the write-enable bit back to 0, allowing attackers to issue BIOS writes during the timing window [REF-1237]. Race condition leading to a crash by calling a hook removal procedure while other activities are occurring at the same time. chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks. chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks. Unsynchronized caching operation enables a race condition that causes messages to be sent to a deallocated object. Race condition during initialization triggers a buffer overflow. Daemon crash by quickly performing operations and undoing them, which eventually leads to an operation that does not acquire a lock. chain: race condition triggers NULL pointer dereference Race condition in library function could cause data to be sent to the wrong process. Race condition in file parser leads to heap corruption. chain: race condition allows attacker to access an object while it is still being initialized, causing software to access uninitialized memory. chain: race condition for an argument value, possibly resulting in NULL dereference Chain: race condition (CWE-362) might allow resource to be released before operating on it, leading to NULL dereference (CWE-476) Chain: Signal handler contains too much functionality (CWE-828), introducing a race condition (CWE-362) that leads to a double free (CWE-415).
References
af854a3a-2127-422b-91ae-364da2661108
security@apache.org
AFFECTED (from MITRE)
| Vendor |
Product |
Versions |
| Apache Software Foundation |
Apache Kafka Clients |
- 2.8.0 ≤ 3.9.1 [affected]
- 4.0.0 ≤ 4.0.1 [affected]
- 4.1.0 ≤ 4.1.1 [affected]
|
| © 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. |
CPE
REMEDIATION
EXPLOITS
Exploit-db.com
| id |
description |
date |
|
| No known exploits |
POC Github
Other Nist (github, ...)
CAPEC
Common Attack Pattern Enumerations and Classifications
| id |
description |
severity |
| 26 |
Leveraging Race Conditions
The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file. The adversary explores to gauge what level of access they have. The adversary gains access to a resource on the target host. The adversary modifies the targeted resource. The resource's value is used to determine the next normal execution action. The resource is modified/checked concurrently by multiple processes. By using one of the processes, the adversary is able to modify the value just before it is consumed by a different process. A race condition occurs and is exploited by the adversary to abuse the target host. |
High |
| 29 |
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. A typical example is file access. The adversary can leverage a file access race condition by "running the race", meaning that they would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the adversary could replace or modify the file, causing the application to behave unexpectedly. The adversary explores to gauge what level of access they have. The adversary confirms access to a resource on the target host. The adversary confirms ability to modify the targeted resource. The adversary decides to leverage the race condition by "running the race", meaning that they would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the adversary can replace the resource and cause an escalation of privilege. |
High |
Cybersecurity needs ?
Strengthen software security from the outset with our DevSecOps expertise
Integrate security right from the start of the software development cycle for more robust applications and greater customer confidence.
Our team of DevSecOps experts can help you secure your APIs, data pipelines, CI/CD chains, Docker containers and Kubernetes deployments.
Discover this offer
