CVE-2023-34040 | Java Deserialization vulnerability in Spring-Kafka When Improperly Configured

In Spring for Apache Kafka 3.0.9 and earlier and versions 2.9.10 and earlier, a possible deserialization attack vector existed, but only if unusual configuration was applied. An attacker would have to construct a malicious serialized object in one of the deserialization exception record headers. Specifically, an application is vulnerable when all of the following are true: * The user does not configure an ErrorHandlingDeserializer for the key and/or value of the record * The user explicitly sets container properties checkDeserExWhenKeyNull and/or checkDeserExWhenValueNull container properties to true. * The user allows untrusted sources to publish to a Kafka topic By default, these properties are false, and the container only attempts to deserialize the headers if an ErrorHandlingDeserializer is configured. The ErrorHandlingDeserializer prevents the vulnerability by removing any such malicious headers before processing the record.

Published: 2023-08-24 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-34040 is rated Moderate Risk (44.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.16%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-34040

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 21.41% 2.16% -19.25%
2 2026-03-30 27.36% 21.41% -5.95%
3 2025-11-21 27.36%

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-34040

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
1.8 3.4 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.9 [email protected]

Weakness enumeration for CVE-2023-34040

GitHub Security Advisory for CVE-2023-34040

GHSA-crqf-q9fp-hwjw · Severity: high · Ecosystem: maven — Spring-Kafka has Java Deserialization vulnerability When Improperly Configured

Affected software / configurations for CVE-2023-34040

Vendor Product Version Raw CPE
vmware spring_for_apache_kafka >= 2.8.1, <= 2.9.10 cpe:2.3:a:vmware:spring_for_apache_kafka:*:*:*:*:*:*:*:*
vmware spring_for_apache_kafka >= 3.0.0, <= 3.0.9 cpe:2.3:a:vmware:spring_for_apache_kafka:*:*:*:*:*:*:*:*

References for CVE-2023-34040

URL Tags
https://spring.io/security/cve-2023-34040 Mitigation Vendor Advisory
cvelogic Threat Intelligence