Cyber Resilience

CVE-2026-37982

Auth Bypass in Redhat Build Of Keycloak 26.4 – 26.4.12

Published
19 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 6.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0044 36th percentile
Risk Priority 42 floored blend · peak EPSS

Summary

CVE-2026-37982 is a medium-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Redhat Build Of Keycloak. Its CVSS base score is 6.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Manipulation (T1098); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to IA-5 (Authenticator Management) and SC-23 (Session Authenticity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A flaw was found in Keycloak. This authentication vulnerability allows a remote attacker to replay `ExecuteActionsActionToken` tokens within Keycloak's WebAuthn (Web Authentication) flow. By intercepting an execute-actions email link, an attacker can register their own authenticator to a victim's account.…

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This leads to unauthorized enrollment of a hardware-backed credential, enabling persistent account takeover.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1098 Account Manipulation Persistence
Adversaries may manipulate accounts to maintain and/or elevate access to victim systems.
Why these techniques?

Vulnerability enables replay of action tokens to register attacker-controlled WebAuthn credentials on victim accounts, directly mapping to Account Manipulation for persistent unauthorized access.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-9087Same product: Redhat Build Of Keycloak
CVE-2026-9799Same product: Redhat Build Of Keycloak
CVE-2026-9793Same product: Redhat Build Of Keycloak
CVE-2024-7318Same product: Redhat Build Of Keycloak
CVE-2026-4628Same product: Redhat Build Of Keycloak
CVE-2026-3911Same product: Redhat Build Of Keycloak
CVE-2026-9796Same product: Redhat Build Of Keycloak
CVE-2026-9792Same product: Redhat Build Of Keycloak
CVE-2026-9795Same product: Redhat Build Of Keycloak
CVE-2026-4282Same product: Redhat Build Of Keycloak

Affected Assets

redhat
build of keycloak
26.4 — 26.4.12

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • IA-5 Authenticator Management
  • SC-23 Session Authenticity
  • IA-11 Re-authentication
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V10.4.16
  • V10.5.1

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly governs binding and lifecycle of authenticators (WebAuthn), preventing unauthorized enrollment via replayed action tokens.

prevent

Requires cryptographic binding and freshness mechanisms that stop replay of ExecuteActionsActionToken values.

prevent

Forces fresh user re-authentication before sensitive operations such as adding a hardware authenticator.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-04 mostly match
prevents

Protecting and verifying identity assertions prevents replay of captured authentication material.

PR.DS-02 mostly match
prevents

Encryption and integrity protections for data-in-transit directly block capture-replay of credentials or tokens.

DE.CM-01 partial match
prevents

Network monitoring may detect anomalous replays after the fact but does not prevent the design flaw.

PR.AA-03 partial match
prevents

Strong authentication methods can reduce replay risk but do not inherently address captured messages.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Cryptographic protections (e.g., nonces, timestamps, message authentication codes) make captured authentication messages unusable for replay.

prevents

Secure authentication mechanisms directly prevent replay attacks by requiring fresh, non-replayable credentials or tokens.

mitigates

Network security controls such as encryption and integrity protection reduce the feasibility of capturing and replaying authentication traffic.

prevents

Application security requirements can mandate replay-resistant authentication designs, but the control itself does not prescribe the technical measures.

References