Spring Boot: Missing Authentication for Critical Functionality
CVE-2026-22731 is a high-severity missing authentication for critical functionality vulnerability in Spring Boot from Spring, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4.0.3, 3.5.11, 3.4.15 as the first without the flaw, so updating Spring Boot to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Spring Boot to 4.0.3 or 3.5.11 or 3.4.15, whichever matches your release line, or a later version.
- Read the advisory on spring.io for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Spring | Spring Boot | 4.0 up to, but not including, 4.0.3; 3.5 up to, but not including, 3.5.11; 3.4 up to, but not including, 3.4.15 | 4.0.3, 3.5.11, 3.4.15 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.2 | High | CNA (vmware.com) |
| CVSS 3.1 | 8.1 | High | NVD |
Official description
Spring Boot applications with Actuator can be vulnerable to an "Authentication Bypass" vulnerability when an application endpoint that requires authentication is declared under a specific path, already configured for a Health Group additional path. This issue affects Spring Boot: from 4.0 before 4.0.3, from 3.5 before 3.5.11, from 3.4 before 3.4.15. This CVE is similar but not equivalent to CVE-2026-22733, as the conditions for exploit and vulnerable versions are different.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Spring Boot
- 9.1 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 7.0 High severity
- 7.5 High severity
- 9.1 Critical severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 7.8 High severity
- 9.1 Critical severity
- 7.8 High severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
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