VulnerabilityPublished 1 Jun 2026

CVE-2026-40989: Spring Cloud Function · Uncontrolled Recursion

Affects Spring Cloud FunctionSource CVE Database V5

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Not known to be exploited · CVSS 5.7 Medium · fixed in 5.0.2 : update Spring Cloud Function when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

5.7Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.0.2, 4.3.3, 4.2.6 +2

CVSS:3.1/AV:P/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:H

Attack Vector: Physical
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Changed
Confidentiality: None
Integrity: Low
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Physical: The attack requires the attacker to physically touch or manipulate the vulnerable component. Physical interaction may be brief or persistent.
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
SpringSpring Cloud Function	Affected >=5.0.0 <5.0.2	Fixed in 5.0.2
SpringSpring Cloud Function	Affected >=4.3.0 <4.3.3	Fixed in 4.3.3
SpringSpring Cloud Function	Affected >=4.2.0 <4.2.6	Fixed in 4.2.6
SpringSpring Cloud Function	Affected >=4.1.0 <4.1.10	Fixed in 4.1.10
SpringSpring Cloud Function	Affected >=3.2.0 <3.2.16	Fixed in 3.2.16
Mavenorg.springframework.cloud/spring-cloud-function`pkg:maven/org.springframework.cloud/spring-cloud-function`Other threats	Affected 3.2.0 – 5.0.0 5 affected builds	Fixed in–

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

AI-suggested

If you cannot patch yet, consider limiting exposure of affected components and monitoring for abnormal resource usage related to recursion in the routing layer.

Description

CVE-2026-40989 is a medium severity vulnerability in Spring Cloud Function involving uncontrolled recursion in the routing layer. This flaw can cause an out-of-memory (OOM) condition, resulting in denial of service. It does not affect confidentiality but impacts availability due to resource exhaustion. The vulnerability affects specific versions of Spring Cloud Function.

Impact

The vulnerability does not compromise confidentiality or integrity but can cause denial of service through resource exhaustion (out-of-memory). This can disrupt availability of applications using affected versions of Spring Cloud Function.

Summary

CVE-2026-40989 is a vulnerability classified under CWE-674 (Uncontrolled Recursion) found in Spring Cloud Function. The issue arises from uncontrolled recursion in the routing layer, which can lead to excessive memory consumption and ultimately an out-of-memory error. This results in denial of service by exhausting system resources. The vulnerability affects multiple specific versions of Spring Cloud Function, namely 3.2.0, 4.1.0, 4.2.0, 4.3.0, and 5.0.0. There is no confirmed remediation or patch available as per the provided data.

CWE-674Uncontrolled Recursion (opens in a new tab)
Class weakness
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
Implementation
Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.
Implementation
Increase the stack size.
Attack patterns
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

spring.io/security/cve-2026-40989 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Jul 2026, 10:25 UTC

WeaknessesCWE-674

Technical details

References

Community reviews

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