Red Hat Security Advisory: Red Hat build of Keycloak 26.4.17 Security Update
Affects Red HatSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.3 Critical · fixed in Red Hat package updates →: patch Red Hat bcprov as a priority.
Data as of 6 Nov 2026, 23:24 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.85, 2.73.12, 2.1.3 +2
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/U:AmberBase metrics
- Attack Vector
- Network
- Attack Complexity
- Low
- Attack Requirements
- None
- Privileges Required
- None
- User Interaction
- None
- Vulnerable system confidentiality
- High
- Vulnerable system integrity
- High
- Vulnerable system availability
- None
- Subsequent system confidentiality
- None
- Subsequent system integrity
- None
- Subsequent system availability
- None
Supplemental metrics
- Provider Urgency
- Amber
Bold values are the worst case: easiest to exploit or largest impact.
- Attack Vector: Network
- The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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
- The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
- Attack Requirements: None
- The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
- Privileges Required: None
- The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
- User Interaction: None
- The vulnerable system can be exploited without interaction from any human user, other than the attacker.
- Vulnerable system confidentiality: High
- There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
- Vulnerable system integrity: High
- There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
- Vulnerable system availability: None
- There is no impact to availability within the Vulnerable System.
- Subsequent system confidentiality: None
- There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
- Subsequent system integrity: None
- There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
- Subsequent system availability: None
- There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
- Provider Urgency: Amber
- Provider has assessed the impact of this vulnerability as having a moderate urgency.
Definitions: FIRST CVSS v4.0 specification.
Exploitation evidence
Disclosed: evidence found.
CVE published 3 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 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.
- Weaponized
- A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity 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
Upgrade BC-JAVA and Legion of the Bouncy Castle Inc./bcprov to 1.85; BC-LTS-JAVA and Legion of the Bouncy Castle Inc./bcprov-lts8on to 2.73.12; BC-FJA and Legion of the Bouncy Castle Inc./bc-fips to 2.1.3, 2.0.2 or 1.0.2.7.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Legion of the Bouncy Castle Inc.BC-JAVA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-LTS-JAVA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-FJA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-FJA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-FJA | Affected
| Fixed in
|
MavenLegion of the Bouncy Castle Inc./bcprovpkg:maven/Legion of the Bouncy Castle Inc./bcprovOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released updated packages for the Red Hat build of Keycloak 26.4.17 that address these vulnerabilities. Users should back up their existing installations, including applications, configuration files, and databases, before applying the update. Applying the official update from Red Hat is the recommended remediation. No alternative mitigations or workarounds are specified in the advisory.
Description
Red Hat has issued a security update for its build of Keycloak 26.4.17 addressing multiple vulnerabilities. These include issues such as account takeover via authentication race conditions, unauthenticated denial of service attacks, cryptographic signature bypasses, SQL injection, HTTP request smuggling, and various bypasses of security controls in SAML and token validation. The update fixes a broad range of security flaws affecting authentication, authorization, and denial of service vectors.
Impact
The vulnerabilities fixed in this update could allow attackers to perform account takeover, unauthorized resource access, denial of service attacks, cryptographic signature bypass, SQL injection leading to data exfiltration and authorization bypass, HTTP request smuggling, and other attacks that compromise the confidentiality, integrity, and availability of the Keycloak server and its managed identities. These issues affect authentication flows, token validation, SAML processing, and cryptographic operations, potentially enabling attackers to impersonate users, escalate privileges, or disrupt service availability.
- CWE-295Improper Certificate Validation (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not validate, or incorrectly validates, a certificate.
Architecture and Design · Implementation
Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
Implementation
If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
- OWASP Cheat Sheets
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
- OWASP Cheat Sheets
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-770Allocation of Resources Without Limits or Throttling (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #25
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Architecture and Design
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended.
- OWASP Cheat Sheets
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
- OWASP Cheat Sheets
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-173Improper Handling of Alternate Encoding (opens in a new tab)
Variant weakness
The product does not properly handle when an input uses an alternate encoding that is valid for the control sphere to which the input is being sent.
Architecture and Design · Input Validation
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
- OWASP Cheat Sheets
- OWASP ASVS 4.0.3
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-1333Inefficient Regular Expression Complexity (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
Architecture and Design
Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
System Configuration
Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
Implementation
Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.
- OWASP Cheat Sheets
- OWASP ASVS 4.0.3
- Attack patterns
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-444Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling) (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
Implementation
Use a web server that employs a strict HTTP parsing procedure, such as Apache.
Implementation
Use only SSL communication.
Implementation
Terminate the client session after each request.
- OWASP Cheat Sheets
- OWASP ASVS 4.0.3
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-823Use of Out-of-range Pointer Offset (opens in a new tab)
Base weakness
The product performs pointer arithmetic on a valid pointer, but it uses an offset that can point outside of the intended range of valid memory locations for the resulting pointer.
- OWASP Cheat Sheets
- Attack patterns
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-89Improper Neutralization of Special Elements used in an SQL Command (SQL Injection) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #2OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Parameterization
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
Architecture and Design · Operation · Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment.
- OWASP Cheat Sheets
- Attack patterns
- Command Line Execution through SQL Injection (opens in a new tab)
- Object Relational Mapping Injection (opens in a new tab)
- SQL Injection through SOAP Parameter Tampering (opens in a new tab)
- Expanding Control over the Operating System from the Database (opens in a new tab)
- SQL Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
- OWASP Cheat Sheets
- OWASP ASVS 4.0.3
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-287Improper Authentication (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
- OWASP Cheat Sheets
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-1035OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities (opens in a new tab)
CategoryOWASP Top 10 A03:2025: Software Supply Chain Failures (opens in a new tab)
Weaknesses in this category are related to the A9 category in the OWASP Top Ten 2017.
MITRE does not allow mapping vulnerabilities to this entry; it groups weaknesses rather than naming one.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- OWASP Cheat Sheets
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-362Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition) (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Architecture and Design
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Architecture and Design
Use thread-safe capabilities such as the data access abstraction in Spring.
Architecture and Design
Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
- OWASP ASVS 4.0.3
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
- CWE-835Loop with Unreachable Exit Condition (Infinite Loop) (opens in a new tab)
Base weakness
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
- GCVE source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory ID
- RHSA-2026:95759
- Vendor Severity
- high
- CVE Count
- 38
- Additional Cves
- CVE-2026-12860, CVE-2026-13506, CVE-2026-18217, CVE-2026-19611, CVE-2026-58059, CVE-2026-59903, CVE-2026-75595, CVE-2026-77874, CVE-2026-82965, CVE-2026-92855, CVE-2026-92857, CVE-2026-93488, CVE-2026-93491, CVE-2026-93492, CVE-2026-93558, CVE-2026-93562, CVE-2026-93564, CVE-2026-93565, CVE-2026-93566, CVE-2026-93567, CVE-2026-93568, CVE-2026-93569, CVE-2026-93573, CVE-2026-93574, CVE-2026-93579, CVE-2026-93998, CVE-2026-96453, CVE-2026-96547, CVE-2026-97175, CVE-2026-97367, CVE-2026-97847, CVE-2026-97848, CVE-2026-103112, CVE-2026-107602, CVE-2026-110879, CVE-2026-110931, CVE-2026-114232
References
Community reviews
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