Security readout for executives and security teams
Plain-English summary
Keycloak login flows may be manipulated when applications permit overly broad redirect URIs. A victim must follow a crafted link, and the application must favor duplicated attacker-controlled response parameters. Successful abuse could bypass security controls or provide unauthorized access, with limited confidentiality and integrity impact indicated by the CVSS assessment.
Executive priority
Prioritize prompt remediation for internet-facing identity systems or clients using broad redirects. The issue is medium severity and exploitation has prerequisites, but identity-control bypass can amplify business impact. Address it in the normal security-update cycle, accelerating systems protecting sensitive or privileged access.
Technical view
CVE-2026-9689 is HTTP parameter pollution in Keycloak’s OIDC redirect handling. An unauthenticated remote attacker may introduce duplicate response parameters through a crafted URI. Exploitation requires user interaction, high attack complexity, permissive redirect configuration, and unsafe parameter precedence in the relying client. CVSS 3.1 is 4.2.
Likely exposure
Exposure is most likely where listed Red Hat build of Keycloak packages are deployed, clients accept broad redirect URIs, and applications mishandle duplicate parameters. The bundle lists specific 26.4 and 26.6 package builds as affected, while 26.4.14 and 26.6.5 product records are marked unaffected.
Exploitation context
The supplied bundle does not identify this CVE as KEV and provides no evidence of active exploitation. Practical attacks require a crafted link, victim interaction, permissive redirect settings, and favorable client-side parameter handling. These dependencies reduce likelihood but do not eliminate authentication-bypass risk.
Researcher notes
The decisive exposure factors are redirect-URI breadth and the relying client’s duplicate-parameter precedence. The bundle does not establish affected upstream Keycloak ranges beyond the listed Red Hat records. Validate exact package builds and configuration; do not infer that every 26.4 or 26.6 deployment is affected.
Mitigation direction
- Apply the applicable Red Hat security updates identified in the listed RHSAs.
- Restrict OIDC clients to exact, trusted redirect URIs wherever operationally possible.
- Ensure client applications reject or safely handle duplicated authentication response parameters.
- Review current Red Hat guidance before selecting replacement package builds.
Validation and detection
- Inventory Keycloak product versions and exact Red Hat package build identifiers.
- Compare installed packages against affected and unaffected records in Red Hat guidance.
- Audit every OIDC client for wildcard or otherwise broad redirect URI patterns.
- Test that relying applications reject ambiguous duplicated response parameters.
- Review authentication logs for suspicious redirect requests and duplicated parameters.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1288: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-9689 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N1.62.5redhatVulnerability scoring details
Base CVSS 3.1 score
4.2MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- Source timelineredhat
Reported to Red Hat.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineredhat
Made public.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2026:50846CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50847CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50848CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50849CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-9689CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2481845CVE reference, redhat · issue-tracking, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Validation of Consistency within Input
Improper Validation of Consistency within Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.