# CVE-2026-118030: Keycloak-services: keycloak-services: hotp race condition allows single otp code reuse across concurrent logins


- **Severity:** Medium 4.2 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-hx7p-ffjf-vx59

## What is CVE-2026-118030?

CVE-2026-118030 is a medium-severity vulnerability in Red Hat Build of Keycloak, published on 29 Oct 2026. 

### Official description

A flaw was found in the HOTP authentication mechanism of the keycloak-services component, which provides identity and access management services. The issue occurs because the system validates a one-time password and updates its internal counter in two separate steps without proper locking. An attacker with a users password could exploit this timing gap to use a single one-time code to log in multiple times simultaneously.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-118030?


## How do I fix CVE-2026-118030?

No fix has been published for CVE-2026-118030 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-118030 being exploited?

There is no known exploitation of CVE-2026-118030 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-118030 and fix it if it is affected.

What it is: CVE-2026-118030 is a medium-severity vulnerability in Red Hat Build of Keycloak, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-118030 in the wild and no public exploit code.

Affected product: Red Hat Build of Keycloak. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-118030/ (Markdown: https://insights.sbomify.com/CVE-2026-118030/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-118030
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-118030
- OSV: https://osv.dev/vulnerability/CVE-2026-118030

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-118030/
Summaries are generated and may contain mistakes; the official description above is the record.