Red Hat Directory Server 11.5 E4S for RHEL 8: Improper Authentication
CVE-2026-18922 is a critical-severity improper authentication vulnerability in Red Hat Directory Server 11.5 E4S for RHEL 8 from Red Hat, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Red Hat Directory Server 11.5 E4S for RHEL 8 you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
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
- LowNo special conditions are needed; the attack works reliably.
- 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:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (redhat.com).
Official description
A flaw was found in 389 Directory Server. During SASL PLAIN authentication, a stale identity carried in a Cyrus SASL auxiliary property from a prior failed bind attempt can be installed on a connection following a subsequent, unrelated successful bind, regardless of which SASL mechanism completes that second bind. An attacker can send a SASL PLAIN bind as cn=Directory Manager with an incorrect password, then complete a SASL ANONYMOUS bind on the same connection, causing the server to grant Directory Manager authority without any valid credentials. A variant using a valid low-privileged account's own successful bind instead of an anonymous one is also possible.
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
- access.redhat.com/errata/RHSA-2026:64771
- access.redhat.com/errata/RHSA-2026:64776
- access.redhat.com/errata/RHSA-2026:64778
- access.redhat.com/errata/RHSA-2026:64779
- access.redhat.com/errata/RHSA-2026:64780
- access.redhat.com/errata/RHSA-2026:64781
- access.redhat.com/errata/RHSA-2026:64783
- access.redhat.com/errata/RHSA-2026:64784
- access.redhat.com/errata/RHSA-2026:64785
- access.redhat.com/errata/RHSA-2026:64789
- access.redhat.com/errata/RHSA-2026:64790
- access.redhat.com/errata/RHSA-2026:64791
- access.redhat.com/errata/RHSA-2026:64792
- access.redhat.com/errata/RHSA-2026:64793
- access.redhat.com/errata/RHSA-2026:64804
Other vulnerabilities in Red Hat Directory Server 11.5 E4S for RHEL 8
- 8.4 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
- 9.8 Critical severity
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