CVE-2026-42998

Exp

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.

Published: 2026-05-28 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42998 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-42998

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-42998

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-29 — 0.06% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42998

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.0 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.8 3.7 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]

Weakness enumeration for CVE-2026-42998

GitHub Security Advisory for CVE-2026-42998

GHSA-8f8m-wrvr-wcvf · Severity: medium — An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone application credential...

OS Trackers for CVE-2026-42998

vendor priority summary link
debian not yet assigned CVE-2026-42998 not yet assigned priority: Debian including 1 source packages (keystone), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-42998
ubuntu medium CVE-2026-42998 medium priority: Ubuntu including 1 source packages (keystone), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 7, released 1. https://ubuntu.com/security/CVE-2026-42998

Affected software / configurations for CVE-2026-42998

Vendor Product Version Raw CPE
openstack keystone >= 14.0.0, < 27.0.2 cpe:2.3:a:openstack:keystone:*:*:*:*:*:*:*:*
openstack keystone >= 28.0.0, < 28.0.2 cpe:2.3:a:openstack:keystone:*:*:*:*:*:*:*:*
openstack keystone >= 29.0.0, < 29.0.2 cpe:2.3:a:openstack:keystone:*:*:*:*:*:*:*:*

References for CVE-2026-42998

URL Tags
https://bugs.launchpad.net/keystone/+bug/2148477 Exploit Issue Tracking Third Party Advisory Patch
https://security.openstack.org/ossa/OSSA-2026-015.html Vendor Advisory Patch
cvelogic Threat Intelligence