CVE-2026-0707Keycloak: keycloak authorization header parsing leading to potential security control bypass
- 5.3MediumCVSS base score
- 0.40%Exploitation in 30 daysEPSS · top 65% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A flaw was found in Keycloak. The Keycloak Authorization header parser is overly permissive regarding the formatting of the "Bearer" authentication scheme. It accepts non-standard characters (such as tabs) as separators and tolerates case variations that deviate from RFC 6750 specifications.
Timeline
ID reserved
By redhat
Published
- 5 months later
· 5 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 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVDNVD · Deferred | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.40% · top 65% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4.10-1 – < *
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4-12 – < *
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4-12 – < *
Red Hat · Red Hat build of Keycloak 26.4.10
All versions: unaffected
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.keycloak:keycloak-parentGHSA-gv94-wp4h-vv8p (opens in a new tab)
What to do
Workaround: To mitigate this issue, configure any front-end security controls, such as Web Application Firewalls (WAFs) or reverse proxies, to strictly validate and normalize the `Authorization` header before forwarding requests to Keycloak. This ensures that only standard Bearer token formats are processed, preventing potential bypasses.
References
References5
- RHSA-2026:3947 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:3948 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-0707 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2427768 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://github.com/keycloak/keycloak/issues/49433 (opens in a new tab)
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-2026-1461 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-gv94-wp4h-vv8p (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-2026-0707)Record last updated .