Security readout for executives and security teams
Plain-English summary
CVE-2026-1035 weakens Keycloak refresh token rotation under a race condition. If an authenticated user can send concurrent refresh requests, strict single-use refresh token enforcement may be bypassed, allowing multiple access tokens from one refresh token. Red Hat rates this Low severity with limited integrity impact.
Executive priority
Treat as a routine security update unless Keycloak refresh token rotation is central to your risk controls. The issue is low severity, requires authentication and race timing, and has no cited active exploitation. Patch through normal Red Hat advisory processes, with higher priority for internet-facing identity services.
Technical view
In Red Hat build of Keycloak 26.4, TokenManager refresh token validation and usage update are not atomic when strict refresh token rotation is enabled. This CWE-367 TOCTOU flaw can let concurrent refresh operations evade reuse detection. CVSS is 3.1: network-accessible, high complexity, low privileges required, no user interaction, integrity impact only.
Likely exposure
Exposure appears limited to listed affected Red Hat build of Keycloak 26.4 packages and versions. Environments not using strict refresh token rotation may not encounter this specific control bypass. Red Hat lists Red Hat build of Keycloak 26.4.11, JBoss EAP 8, EAP Expansion Pack, and Red Hat Single Sign-On 7 as unaffected.
Exploitation context
No active exploitation is indicated in the provided sources, and the CVE is not listed as KEV. Successful abuse requires an authenticated context and a timing race, reflected by high attack complexity and low privileges required. The impact is undermining refresh token reuse protection, not direct data disclosure or service outage.
Researcher notes
The key issue is non-atomic check-and-update behavior in refresh token reuse enforcement. Sources do not provide implementation patch details beyond Red Hat advisories. Avoid assuming upstream community Keycloak exposure unless confirmed by vendor data; the provided affected list is specific to Red Hat build packages.
Mitigation direction
- Review Red Hat advisories RHSA-2026:6477 and RHSA-2026:6478 for fixed package guidance.
- Identify deployments running affected Red Hat build of Keycloak 26.4 packages.
- Prioritize updates where strict refresh token rotation is a relied-upon security control.
- If unsure, check Red Hat CVE guidance before changing token settings.
Validation and detection
- Inventory Keycloak package names and versions against Red Hat's affected list.
- Confirm whether strict refresh token rotation is enabled in relevant realms or clients.
- Verify installed packages match Red Hat advisory fixed or unaffected status.
- Monitor authentication logs for unusual repeated refresh activity from the same session context.
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-367: 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-1035 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
- Low
- CVSS
- 3.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/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.
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:L/UI:N/S:U/C:N/I:L/A:N1.61.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
3.1LowVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2026:6477CVE reference · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:6478CVE reference · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-1035CVE reference · vdb-entry, x_refsource_REDHAT
- RHBZ#2430314CVE reference · 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.
Time-of-check Time-of-use (TOCTOU) Race Condition
Time-of-check Time-of-use (TOCTOU) Race Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.