CVE-2026-3872Keycloak: keycloak: information disclosure due to redirect_uri validation bypass
- 7.3HighCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 61% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A flaw was found in Keycloak. This issue allows an attacker, who controls another path on the same web server, to bypass the allowed path in redirect Uniform Resource Identifiers (URIs) that use a wildcard. A successful attack may lead to the theft of an access token, resulting in information disclosure.
Timeline
ID reserved
By redhat
- 23 days later
· 23 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | High7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |
| redhat-SADPADP (enrichment) | 3.1 | High7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |
| NVDNVD · Modified | 3.1 | High7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.45% · top 61% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.3.
Affected products
Red Hat · Red Hat build of Keycloak 26.2
- unaffected 26.2.15-1 – < *
Red Hat · Red Hat build of Keycloak 26.2
- unaffected 26.2-18 – < *
Red Hat · Red Hat build of Keycloak 26.2
- unaffected 26.2-18 – < *
Red Hat · Red Hat build of Keycloak 26.2.15
All versions: unaffected
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4.11-1 – < *
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4-14 – < *
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4-14 – < *
Red Hat · Red Hat build of Keycloak 26.4.11
All versions: unaffected
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.keycloak:keycloak-servicesGHSA-cjm2-j6cm-6p6m (opens in a new tab)
What to do
Workaround: To mitigate this vulnerability, avoid using wildcards in `redirect_uri` configurations within Keycloak. Restricting `redirect_uri` to explicit, fully qualified URIs prevents the bypass of validation logic. This configuration change may require a service restart or reload to take effect.
References
References7
- RHSA-2026:6475 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:6476 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:6477 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:6478 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-3872 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2445988 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3872.json (opens in a new tab)x_sadp-csaf-vex
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-18206 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-cjm2-j6cm-6p6m (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-3872)Record last updated .