Cyber Resilience

CVE-2026-42998

MediumPublic PoCUpdated

Published: 28 May 2026

Published
28 May 2026
Modified
17 June 2026
KEV Added
Patch
CVSS Score v3.1 6.0 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
EPSS Score 0.0030 22.1th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-42998 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Openstack Keystone. Its CVSS base score is 6.0 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Cloud Accounts (T1078.004); ranked at the 22.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

No EU or UK CSIRT advisories indexed for this CVE.

Vulnerability details

An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone application credential authentication plugin does not verify that the user supplied in the authentication request matches the owner of the application credential. An attacker can authenticate with their own…

more

application credential ID and secret while specifying a different user's name and domain in the request body. Keystone issues a token attributed to the victim user. The impersonated token is project-scoped and carries the intersection of the application credential's roles and the victim's actual roles on the project. This enables audit evasion, reading the victim's credentials, and acting as the victim within shared projects.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1078.004 Cloud Accounts Stealth
Valid accounts in cloud environments may allow adversaries to perform actions to achieve Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
T1134.001 Token Impersonation/Theft Stealth
Adversaries may duplicate then impersonate another user's existing token to escalate privileges and bypass access controls.
Why these techniques?

Auth plugin flaw directly allows issuance of victim-scoped tokens via attacker-controlled app credentials, enabling cloud account impersonation and token misuse.

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

Affected Assets

openstack
keystone
14.0.0 — 27.0.2 · 28.0.0 — 28.0.2 · 29.0.0 — 29.0.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-863

Periodic review and update of procedures reduces incorrect authorization implementations over time.

addresses: CWE-863

Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.

addresses: CWE-863

Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.

addresses: CWE-863

The authorization process and usage restrictions help prevent incorrect authorization for remote access types.

addresses: CWE-863

Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.

addresses: CWE-863

Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.

addresses: CWE-863

Monitoring account use, notifying on changes, and reviewing accounts for compliance corrects incorrect authorization assignments.

addresses: CWE-863

Ensures authorization decisions for external system use are correctly implemented and enforced.

References