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Full vulnerability report · 2026
CVE-2026-9793High confidence

Keycloak: keycloak: security policy bypass in jwe-encrypted request object processing

Red Hat · Red Hat build of Keycloak 26.4

Official source article: Red Hat RHSA-2026:50846 ↗. Check the applicable product and release in the original source.

5.9MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.26% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Red Hat Red Hat build of Keycloak 26.4 and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Open-source package ranges2 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
Mavenorg.keycloak:keycloak-servicesECOSYSTEM: introduced 0; last affected 26.6.4Not statedOSV record ↗aggregator derived · 10 Sep 2026
mavenorg.keycloak:keycloak-services<= 26.6.4Not statedGitHub advisory ↗github reviewed aggregator · 5 Aug 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-9793 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykeycloak: Keycloak: Security policy bypass in JWE-encrypted request object processing
20 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • rhbk/keycloak-operator-bundle@sha256:2c25b3107aee4f1fc25530f099fa683ba3077c185d581e7caa777c4410383085_amd64 as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9-operator@sha256:0d3ea94f75c1b4528722db2c216ff2267ec17ba16adf3f703afb82354f0fdc68_arm64 as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9-operator@sha256:330350e0cd77afca88886156c2668ae4bca75865e90362cbcf9657197bfa21e8_amd64 as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9-operator@sha256:399c59b8e63de5b6aa4e64008644550b98feb0957214e58dc7c6a5246dde3c87_ppc64le as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9-operator@sha256:f9f35a75d3029edf5ff82351c0b60ad0dd8672c3fa8f22f672954c248f9e0c63_s390x as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9@sha256:130dfc422476647b5098a317a38964e7ea6a2a3f1a63d91f91dfb993921b356b_ppc64le as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9@sha256:8a6fd6c12811ce179fc1248c63a152d173c12866b84f8b8364f4f3ed42b7ba58_s390x as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9@sha256:cc475d34ac199de0908a32efa630c219469076feb74fd970d617c40cc90911f8_arm64 as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-rhel9@sha256:fc0390f65497ad6274f3db55ac796eb792255a8780578ab4d98aec9f42c23bc0_amd64 as a component of Red Hat build of Keycloak 26.4
  • rhbk/keycloak-operator-bundle@sha256:06ee2f18c4218c9a095360efa2023b2080aa81e04a08363dbcb1d14de85a5d0d_amd64 as a component of Red Hat build of Keycloak 26.6
  • rhbk/keycloak-rhel9-operator@sha256:0024d9a0b69b61004a0d35ee25eefc443fe75ce2563b1645ec318caacc0aa23c_s390x as a component of Red Hat build of Keycloak 26.6
  • rhbk/keycloak-rhel9-operator@sha256:2eeef9cec3ee8e3cfdb1c4b7377582b4a5378f852e11872eeb74597ad9ec0615_amd64 as a component of Red Hat build of Keycloak 26.6
Summary
A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.
Remediation
Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-32707

No EUVD known-exploited evidence

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
5.9 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

What

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

Why

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

Why

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Verification of Cryptographic Signature → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-347 ↗

CWE-347: Improper Verification of Cryptographic Signature. The product does not verify, or incorrectly verifies, the cryptographic signature for data.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-347
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-32707Official EUVD mapping

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

Official EUVD record ↗
BSI · German · WID-SEC-2026-1708Keycloak: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Keycloak ausnutzen, um seine Privilegien zu erhöhen, um Informationen offenzulegen, um Sicherheitsvorkehrungen zu umgehen und um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260603Security Bulletin 3 Jun 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 3 Jun 2026, published on 3 June 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-018108レッドハットのbuild of keycloakにおけるデジタル署名の検証に関する脆弱性

Keycloakに脆弱性が発見されました。JSON Web Encryption（JWE）で暗号化されたリクエストオブジェクトが送信された場合、復号された内容が生のJSONであると、Keycloakは署名されていないクレームを誤って処理する可能性があり、設定された署名ポリシーを回避してしまいます。これにより、リモート攻撃者が不正なクレームを送信でき、OpenID Connect（OIDC）認可フロー内のデータ整合性が侵害される恐れがあります。リダイレクトURIの許可リストは補完的な対策として機能しますが、この脆弱性はOIDC CoreおよびFinancial-grade API（FAPI）の署名要件に違反します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 28 May 2026 · Last source change 20 Aug 2026, 00:54 UTC · CWE-347 · Improper Verification of Cryptographic Signature

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-32707
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected versions. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-32707↗Vendor advisory↗Vendor advisory↗CVE authority or vendor reference · Red Hat RHSA-2026:50846↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-9793 · cve.blacktree.nl