Red Hat build of Keycloak 26.2: Improper Verification of Cryptographic Signature
CVE-2026-1529 is a high-severity improper verification of cryptographic signature vulnerability in Red Hat build of Keycloak 26.2 from Red Hat, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.49% 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
- Check which version of Red Hat build of Keycloak 26.2 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.2 | Not specified in the record | Not stated |
| Red Hat | Red Hat build of Keycloak 26.2.13 | Not specified in the record | Not stated |
| Red Hat | Red Hat build of Keycloak 26.4 | Not specified in the record | Not stated |
| Red Hat | Red Hat build of Keycloak 26.4.9 | Not specified in the record | Not stated |
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
- LowA basic user account is enough.
- 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:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (redhat.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.1 | High | CNA (redhat.com) |
| CVSS 3.1 | 8.1 | High | CNA |
Official description
A flaw was found in Keycloak. An attacker can exploit this vulnerability by modifying the organization ID and target email within a legitimate invitation token's JSON Web Token (JWT) payload. This lack of cryptographic signature verification allows the attacker to successfully self-register into an unauthorized organization, leading to unauthorized access.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Verification of Cryptographic Signature
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- access.redhat.com/errata/RHSA-2026:2363
- access.redhat.com/errata/RHSA-2026:2364
- access.redhat.com/errata/RHSA-2026:2365
- access.redhat.com/errata/RHSA-2026:2366
- access.redhat.com/security/cve/CVE-2026-1529
- bugzilla.redhat.com/show_bug.cgi?id=2433783
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1529.json
Other vulnerabilities in Red Hat build of Keycloak 26.2
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 7.4 High severity
Recent Improper Verification of Cryptographic Signature vulnerabilities
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
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