Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Network-reachable auth token bypass requires no credentials or interaction; C:H reflects sensitive data exposure, I:L reflects limited unauthorized operations, A:N as no availability impact is described.
Primary rating from Vendor (ibm).
CVSS VectorNVD
Lifecycle Timeline
5DescriptionNVD
IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to obtain sensitive information and perform unauthorized operations due to improper validation of authentication tokens.
AnalysisAI
Authentication token validation flaws in IBM i 7.3 through 7.6 expose network-reachable systems to remote unauthenticated attackers capable of extracting sensitive information and performing limited unauthorized operations. The CWE-287 root cause (Improper Authentication) combined with a PR:N/AV:N CVSS vector confirms exploitation requires no credentials and no user interaction over the network. No active exploitation has been confirmed (not in CISA KEV), EPSS sits at 0.31% (23rd percentile), and SSVC marks exploitation status as 'none' - signals that collectively moderate urgency despite the 8.2 CVSS score.
Technical ContextAI
IBM i (formerly AS/400 and iSeries) is IBM's proprietary operating system for IBM Power Systems servers, widely deployed in enterprise environments supporting mission-critical workloads in banking, retail, manufacturing, and government. The vulnerability is rooted in CWE-287 (Improper Authentication): the platform fails to properly validate authentication tokens presented to one or more network-accessible services, allowing crafted or malformed tokens to bypass access controls. The relevant CPE string cpe:2.3:a:ibm:i covers all sub-releases across IBM i 7.3, 7.4, 7.5, and 7.6. The CVSS vector AV:N/AC:L/PR:N/UI:N indicates the vulnerable service is directly reachable over the network with no credential or interaction prerequisite from the attacker's side.
RemediationAI
IBM has released a patch addressing this vulnerability, available through the IBM support portal at https://www.ibm.com/support/pages/node/7283569. Administrators should identify and apply the relevant Program Temporary Fix (PTF) for their specific IBM i release level (7.3, 7.4, 7.5, or 7.6); the exact PTF number is not independently confirmed in available intelligence and must be obtained directly from the IBM advisory. As a compensating control prior to patching, restrict network access to IBM i authentication services using host-based exit point controls or perimeter firewall ACLs to limit reachability to known trusted hosts - note that overly broad restrictions may disrupt legitimate remote access and must be tested carefully. Additionally, enable QAUDJRN (IBM i security audit journal) with *AUTFAIL and *SIGNON object auditing to detect anomalous token-based authentication attempts, which can surface exploitation attempts without blocking service.
Same weakness CWE-287 – Improper Authentication
View allSame technique Authentication Bypass
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-58453
GHSA-pcj8-43hf-pqxw