VulnerabilityPublished 11 Nov 2026

CVE-2026-112201: keycloak-services · Concurrent Execution using Shared Resource with Improper Synchronization

Affects keycloak-servicesSource CVE Database V5

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Not known to be exploited · CVSS 4.8 Medium.

Data as of 11 Nov 2026, 12:48 UTC

CVSS 3.1 base score

4.8Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	4.8

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Nov 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 11 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

Affected software

Product	Affected	Fixed in
keycloak-servicesorg.keycloak:keycloak-services	Affected >=26.8.0 <=26.8.1	Fixed in–
GitHuborg.keycloak:keycloak-services`pkg:github/org.keycloak:keycloak-services`Other threats	Affected >=26.8.0 <=26.8.1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

No effective mitigation is currently available that meets Red Hat's criteria for ease of use, applicability, and stability. Users should monitor vendor advisories for future fixes. Upgrading to a fixed version when available is recommended.

Description

A concurrency flaw in Keycloak's login-failure storage component affects multi-node deployments using MySQL or MariaDB. Simultaneous failed login attempts for the same user can cause a synchronization error that locks the user's database record, blocking legitimate login attempts and causing failures. Additionally, some failed attempts may not be recorded properly, potentially bypassing brute-force protection.

Impact

Successful exploitation causes a localized denial of service by blocking legitimate login attempts for specific user accounts. It may also allow attackers to bypass brute-force protection limits due to some failed login attempts not being recorded correctly. The vulnerability does not impact confidentiality but has low integrity and availability impacts.

Summary

CVE-2026-112201 is a vulnerability in Keycloak's login-failure storage mechanism when deployed with MySQL or MariaDB in multi-node configurations. The flaw arises from improper synchronization during concurrent upsert operations relying on database-specific affected-row counts. This race condition can cause the system to enter a repetitive loop locking the user's record, resulting in denial of service for that user and inaccurate brute-force failure counting. The issue is specific to certain database backends and requires a particular race condition to be triggered.

References

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