CVE-2023-34040
A public proof of concept exists; no exploitation attested.
- Published2023-08-24
- WeaknessCWE-502
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
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.
Timeline
dates in UTC- 2023-08-2413:15CVE publishedNVD
- 2026-10-2319:23First public proof of conceptPoC-in-GitHub
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-34040?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-34040?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.x | ≥ 2.8.1, ≤ 2.9.10 | no fix published | NVD |
| 3.0 | ≥ 3.0.0, ≤ 3.0.9 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
Advisories and patches
- spring.ioMitigation · Vendor Advisory
Detection
read 2026-10-23 19:23 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- 4 repositories, unverifiedContrast-Security-OSS/Spring-Kafka-POC-CVE-2023-34040pyn3rd/CVE-2023-34040buiduchoang24/CVE-2023-34040huyennhat-dev/cve-2023-34040 PoC-in-GitHub
Sources
- CISA-ADPSSVC decisionnone2024-10-01
- OpenCVESSVC decisionnone—
- CNACVSS 3.15.3read 2026-10-23
- NVDCVSS 3.17.8read 2026-10-23
- CNAweakness (CWE)CWE-502read 2026-10-23
- NVDweakness (CWE)CWE-502read 2026-10-23
- FIRST EPSSEPSS score2.1 %2026-10-22
- PoC-in-GitHubproof of concept4read 2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Published
- 2023-08-24
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2023-34040?
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What is the CVSS score for CVE-2023-34040?
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