CVE-2026-111496
Description
A flaw was found in Kafka Streams. An attacker with write access to a source topic can cause a Denial of Service (DoS) by submitting a record with an excessively large timestamp. Due to a missing integer overflow check when scheduling periodic stream tasks, the calculation overflows and causes the processing thread to enter an infinite loop, stalling stream execution and rendering the application unresponsive.
Statement
This vulnerability is rated as Moderate impact because exploitation requires authenticated write permissions to a source topic feeding a stream-time punctuation topology, and affects only client-side stream processing threads rather than the core Kafka broker infrastructure. Furthermore, brokers configured with default timestamp boundary checks reject extreme future timestamps, limiting practical exploitability to environments where timestamp validation is disabled or relaxed. If triggered, the flaw results in stream processing thread deadlocks, halting partition consumption until the malformed message is handled.
Mitigation
To reduce exposure to this issue without modifying application binaries:
1. Restrict write access to source topics:
Enforce Kafka Access Control Lists (ACLs) to restrict write permissions on topics consumed by Kafka Streams topologies that rely on stream-time punctuation, ensuring only authorized producers can publish records.
2. Enforce timestamp boundaries on brokers and topics:
Configure timestamp limits on Kafka source topics to reject messages with extreme future timestamps. Apply the topic configuration dynamically using administrative scripts:
kafka-configs.sh --bootstrap-server <broker-host>:<port> --entity-type topics --entity-name <topic-name> --alter --add-config log.message.timestamp.after.max.ms=3600000
Alternatively, enforce `log.message.timestamp.after.max.ms` cluster-wide in the broker configuration file.
Caveats:
Restricting message timestamp boundaries causes brokers to reject records outside the configured time delta, which could disrupt producers with unsynchronized system clocks. If applying changes cluster-wide at the broker configuration level, a service restart or configuration reload of Kafka brokers is required, which may temporarily disrupt active client connections.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided. If the calculated result involves time values, then the product might crash when it encounters a time that is less than the previously-calculated time.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.
Availability,Other
Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.
Access Control
Technical Impact: Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.
Access Control
Technical Impact: Bypass Protection Mechanism; DoS: Crash, Exit, or Restart
If integer values are used in time-based, security-critical decisions, such as calculating expiration times or determining whether an event occurs within a specific time or date range, to cause an incorrect security decision. The consequences could even include "self-DoS" if the overflow produces a time value that is not accounted for in protection mechanism logic [REF-1570].
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