VulnerabilityPublished 8 Jan 2026Updated 8 Jun 2026

CVE-2026-0707: Red Hat build of Keycloak 26.4 · Incorrect Behavior Order: Authorization Before Parsing and Canonicalization

Affects Red Hat build of Keycloak 26.4Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 09:16 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Red HatRed Hat build of Keycloak 26.4	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.4	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.4.10	Affected–	Fixed in–

AI-suggested

Red Hat has released fixed versions of the Red Hat build of Keycloak 26.4.10 standalone server packages and container images that address this vulnerability. Users should back up their existing installations and apply these updates promptly. The vendor advisories RHSA-2026:3947 and RHSA-2026:3948 provide detailed update instructions. No additional mitigations are specified or required beyond applying the official fixes.

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.

Impact

The vulnerability allows potential security control bypass due to improper parsing of the Authorization header's Bearer token. While it does not impact confidentiality or availability, it affects integrity by potentially allowing unauthorized actions or access. There are no known exploits in the wild at this time. The flaw could be leveraged remotely without authentication or user interaction, increasing exposure risk if unpatched.

Summary

The vulnerability in Red Hat build of Keycloak 26.4 involves an overly permissive Authorization header parser that accepts malformed Bearer tokens with non-standard separators and case variations, violating RFC 6750 specifications. This incorrect behavior order—authorizing before proper parsing and canonicalization—may allow attackers to bypass security controls. The issue has a CVSS 3.1 base score of 5.3 (medium severity) with network attack vector, low attack complexity, no privileges required, no user interaction, and impacts integrity only. Red Hat has published security advisories RHSA-2026:3947 and RHSA-2026:3948 that include fixes in Keycloak 26.4.10 standalone packages and container images for OpenShift. Users should update to these fixed versions to remediate the vulnerability.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Jun 2026, 20:01 UTC

Technical details

References

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