CVE-2026-111551VulnerabilityPublished 28 Oct 2026

Several Kafka deserialization paths read a size or count field from input data and use it directly to allocate an

Source GCVE Database

Authoritative record:CVE-2026-111551· High

Not known to be exploited · fixed in 4.2.2 : patch Apache Kafka soon.

Data as of 28 Oct 2026, 22:12 UTC

Severity

High

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

Patch: Available – fixed in 4.2.2

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.

ghsa-fpf4-qx46-w5rg

What to do

Affected software

Product	Affected	Fixed in
Apache Kafkaorg.apache.kafka:kafka-streams	Affected >=0.10.0.0 <=4.1.2 >=4.2.0 <=4.2.1 >=4.3.0 <=4.3.1	Fixed in–
Apache Kafkaorg.apache.kafka:kafka-clients	Affected >=0.10.0.0 <=4.1.2 >=4.2.0 <=4.2.1 >=4.3.0 <=4.3.1	Fixed in–
MavenApache Software Foundation/org.apache.kafka:kafka-streams`pkg:maven/Apache Software Foundation/org.apache.kafka:kafka-streams`Other threats	Affected >=0.10.0.0 <=4.1.2 >=4.2.0 <=4.2.1 >=4.3.0 <=4.3.1	Fixed in–
MavenApache Software Foundation/org.apache.kafka:kafka-clients`pkg:maven/Apache Software Foundation/org.apache.kafka:kafka-clients`Other threats	Affected >=0.10.0.0 <=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 Apache Kafka to versions 4.2.2, 4.3.2, or 4.4.0 where the issue is fixed. Additionally, if authorization is enabled, restrict write access to each application's internal topics and consumer group metadata to the application's own principal. Also restrict who can produce to topics consumed with ListSerde to trusted principals. These measures reduce the risk of crafted malicious inputs triggering the vulnerability.

Description

Several Apache Kafka deserialization paths improperly use size or count fields from input data to allocate memory without verifying the actual available bytes. This can allow an attacker to craft inputs that cause large memory allocations, leading to OutOfMemoryError crashes in Kafka consumers or Kafka Streams threads. The issue affects internal Kafka Streams topics and consumers using ListSerde. The broker and cluster remain unaffected. Fixed in Apache Kafka versions 4.2.2, 4.3.2, and 4.4.0.

Impact

An attacker can cause a denial of service by triggering large memory allocations during deserialization, leading to OutOfMemoryError and crashing Kafka consumer or Kafka Streams threads. This affects only the consumer or Streams application instance processing the crafted input; the Kafka broker and cluster remain unaffected. The crafted malicious record persists in the topic, allowing repeated crashes on restart. The vulnerability can be exploited by writing crafted records to internal Streams topics or topics consumed with ListSerde, or by manipulating consumer group assignment data.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (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)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2026, 19:58 UTC

WeaknessesCWE-20

Technical details

References

Community reviews

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