VulnerabilityPublished 28 Oct 2026

CVE-2026-114349: Apache Kafka · Excessive Memory Allocation

Affects Apache KafkaSource CVE Database V5

Not known to be exploited.

Data as of 28 Oct 2026, 17:23 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Apache Kafkaorg.apache.kafka:kafka	Affected >=0.11.0.0 <=4.1.2 >=4.2.0 <=4.2.1 >=4.3.0 <=4.3.1	Fixed in–
MavenApache Software Foundation/org.apache.kafka:kafka`pkg:maven/Apache Software Foundation/org.apache.kafka:kafka`Other threats	Affected >=0.11.0.0 <=4.1.2 >=4.2.0 <=4.2.1 >=4.3.0 <=4.3.1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade to Apache Kafka versions 4.2.2, 4.3.2, or 4.4.0 where the broker validates the declared decompressed record size against the max.decompressed.message.bytes configuration. After upgrading, set max.decompressed.message.bytes to a bounded value appropriate for your workload to effectively mitigate the issue, as the default is effectively unlimited for backward compatibility. Until upgrade and configuration are possible, restrict Write access to trusted producers. Quotas and max.message.bytes do not mitigate this vulnerability.

Description

CVE-2026-114349 is a vulnerability in Apache Kafka where the broker allocates memory based on an attacker-controlled declared decompressed record size without proper validation. This can lead to OutOfMemoryError conditions, crashing request-handler threads or the broker JVM if configured to exit on such errors. Additionally, crafted records can cause the log-cleaner thread to terminate permanently, stopping log compaction and impacting broker availability. No data disclosure or alteration occurs.

Impact

An authenticated user with Write permission on a topic can cause broker request-handler threads or the entire broker JVM to crash by sending crafted produce requests with maliciously declared decompressed record sizes. This results in denial of service. Additionally, crafted records can cause the log-cleaner thread to terminate permanently, stopping log compaction and affecting broker availability persistently until the offending record is removed. No confidentiality or integrity impact is reported.

Summary

Apache Kafka brokers decode compressed record batches by reading a declared decompressed body size from the stream and allocating a buffer accordingly before validating the size. The declared size is attacker-controlled and can be up to about 2 GiB, which can cause the broker to allocate excessive memory and raise OutOfMemoryError. This affects brokers when the batch's codec differs from the topic's compression type, impacting request-handler threads and consumers. If the broker is started with -XX:+ExitOnOutOfMemoryError, the JVM can terminate on a single crafted request. Furthermore, crafted records accepted at ingest can cause the log-cleaner thread to terminate permanently on compacted topics, halting log compaction including critical internal topics. The vulnerability affects Apache Kafka versions from 0.11.0.0 up to 4.1.2, 4.2.0 to 4.2.1, and 4.3.0 to 4.3.1. The issue is mitigated by validating the decompressed size against a configurable limit max.decompressed.message.bytes introduced in Apache Kafka 4.2.2, 4.3.2, and 4.4.0.

CWE-789Memory Allocation with Excessive Size Value (opens in a new tab)
Variant weakness
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
Implementation · Architecture and Design
Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
Operation
Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-1284Improper Validation of Specified Quantity in Input (opens in a new tab)
Base weakness
The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

kafka.apache.org/cve-list (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2026, 17:23 UTC

WeaknessesCWE-789, CWE-400, CWE-1284

Technical details

References

Community reviews

Related threats