CVE-2023-20863Network attack vector

Application denial of service via oversized SpEL expressions

Published Apr 13, 2023 · Updated Feb 7, 2025

Denial of service in Spring Framework before 5.2.24, 5.3.27, and 6.0.8 allows remote attackers to interrupt applications via crafted SpEL. InternalSpelExpressionParser passed unrestricted expression strings into tokenization and parsing, allowing oversized input to consume excessive resources. Exposure requires an application path that supplies attacker-controlled SpEL to the parser, and exploitation affects application availability only.

CVSS severity7.5
High
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Spring Framework before 5.2.24, 5.3.27, and 6.0.8 allows remote attackers to interrupt applications via crafted SpEL. InternalSpelExpressionParser passed unrestricted expression strings into tokenization and parsing, allowing oversized input to consume excessive resources. Exposure requires an application path that supplies attacker-controlled SpEL to the parser, and exploitation affects application availability only.

The record

CVE
CVE-2023-20863
Published
Apr 13, 2023
Updated
Feb 7, 2025
Vendor
Spring
Product
Spring Framework
Classifications
CWE-917, CWE-400, CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Spring framework versions 5.2.x.release prior to 5.2.24.release+, 5.3.x prior to 5.3.27+, 6.0.x prior to 6.0.8+ and older unsupported versions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Spring · Spring Frameworkversion=Spring framework versions 5.2.x.release prior to 5.2.24.release+, 5.3.x prior to 5.3.27+, 6.0.x prior to 6.0.8+ and older unsupported versions

Published CVSS scores

7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-917Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
CWE-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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