Spring LDAP: Improper Authentication
CVE-2026-41720 is a high-severity improper authentication vulnerability in Spring LDAP from Spring, with a CVSS 3.1 base score of 7.4 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 2.4.5, 3.2.18, 3.3.7.1 as the first without the flaw, so updating Spring LDAP to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.26% 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 LDAP to 2.4.5 or 3.2.18 or 3.3.7.1 or 4.0.3.1, whichever matches your release line, or a later version.
- 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 LDAP | 2.4.0 up to, but not including, 2.4.5; 3.2.0 up to, but not including, 3.2.18; 3.3.0 up to, but not including, 3.3.7.1; 4.0.0 up to, but not including, 4.0.3.1 | 2.4.5, 3.2.18, 3.3.7.1, 4.0.3.1 |
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
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (vmware.com).
Official description
Spring LDAP's DirContextAuthenticationStrategy implementations do not reject a bind request where a non-empty username is paired with an empty or null password. Affected versions: Spring LDAP 2.4.0 through 2.4.4; 3.2.0 through 3.2.17; 3.3.0 through 3.3.7; 4.0.0 through 4.0.3.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Authentication vulnerabilities
- 7.3 High severity
- 9.3 Critical severity
- 7.0 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.3 High severity
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