CVE-2026-42998 OpenStack Keystone doesn't verify that the user supplied in the authentication request matches the owner of the application credential
Attackers can impersonate other users by mismatching application credential owners, enabling audit evasion and unauthorized access in OpenStack Keystone.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42998?
CVE-2026-42998 is a medium-severity authentication bypass vulnerability in OpenStack Keystone, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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 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.
Weakness: CWE-863
Which versions are affected by CVE-2026-42998?
7 open source packages ship an affected version, including keystone. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
keystone PyPI | From 14.0.0 | 27.0.2, 28.0.2, 29.0.2 |
keystone PyPI | From 14.0.0 | 27.0.2 |
keystone PyPI | From 14.0.0 | 27.0.2 |
keystone PyPI | From 28.0.0 | 28.0.2 |
keystone PyPI | From 28.0.0 | 28.0.2 |
keystone PyPI | From 29.0.0 | 29.0.2 |
1 more packages
keystone PyPI | From 29.0.0 | 29.0.2 |
Products include Openstack Keystone.
How do I fix CVE-2026-42998?
Upgrade keystone to a fixed version for your release line: 27.0.2, 28.0.2 or 29.0.2.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-42998 being exploited?
There is no known exploitation of CVE-2026-42998 in the wild and no public exploit code.
Other vulnerabilities in OpenStack Keystone
- CVE-2020-12690 Insufficient Session Expiration in OpenStack Keystone
- CVE-2019-19687 OpenStack Keystone Credential Leakage
- CVE-2026-43001 OpenStack Keystone has an Incorrect Authorization Issue
- CVE-2014-2828 OpenStack Identity (Keystone) DoS through V3 API authentication chaining
- CVE-2021-38155 OpenStack Keystone allows information disclosure during account locking
Sources
Also known as DEBIAN-CVE-2026-42998, GHSA-8f8m-wrvr-wcvf, PYSEC-2026-599.