BlackTreeCVE Intelligence
← Back to the CVE catalogue
Full vulnerability report · 2026
CVE-2026-16849High confidence

Vulnerabilities in IBM AIX and PowerVM VIOS

IBM · AIX

4.3MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.28% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs IBM AIX and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-62744

No EUVD known-exploited evidence

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an improper check for an array index boundary.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
4.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an improper check for an array index boundary.

What

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an improper check for an array index boundary.

Why

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an improper check for an array index boundary.

Why

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
an adjacent network → Improper Validation of Array Index → disrupt the affected service
Attack surface
Adjacent
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-129 ↗

CWE-129: Improper Validation of Array Index. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.ALowAvailability impact: A successful attack can cause a limited loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
UnauthenticatedDenial of serviceCWE-129
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-62744Official EUVD mapping

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an improper check for an array index boundary.

Official EUVD record ↗
BSI · German · WID-SEC-2026-2858IBM AIX und VIOS: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM AIX und IBM VIOS ausnutzen, um beliebigen Programmcode auszuführen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren, und um Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260826Security Bulletin 26 Aug 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 26 Aug 2026, published on 26 August 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1067Multiples vulnérabilités dans les produits IBM

d?id=CVE-2026-16839 Référence CVE CVE-2026-16840 https://www.cve.org/CVERecord?id=CVE-2026-16840 Référence CVE CVE-2026-16841 https://www.cve.org/CVERecord?id=CVE-2026-16841 Référence CVE CVE-2026-16842 https://www.cve.org/CVERecord?id=CVE-2026-16842 Référence CVE CVE-2026-16844 https://www.cve.org/CVERecord?id=CVE-2026-16844 Référence CVE CVE-2026-16845 https://www.cve.org/CVERecord?id=CVE-2026-16845 Référence CVE CVE-2026-16846 https://www.cve.org/CVERecord?id=CVE-2026-16846 Référence CVE CVE-2026-16847 https://www.cve.org/CVERecord?id=CVE-2026-16847 Référence CVE CVE-2026-16848 https://www.cve.org/CVERecord?id=CVE-2026-16848 Référence CVE CVE-2026-16849 https://www.cve.org/CVERecord?id=CVE-2026-16849 Référence CVE CVE-2026-16850 https://www.cve.org/CVERecord?id=CVE-2026-16850 Référence CVE CVE-2026-16851 https://www.cve.org/CVERecord?id=CVE-2026-16851 Référence CVE CVE-2026-16852 https://www.cve.org/CVERecord?id=CVE-2026-16852 Référence CVE CVE-2026-16855 https://www.cve.org/CVERecord?id=CVE-2026-16855 Référence CVE CVE-2026-16857 https://www.cve.org/CVERecord?id=CVE-2026-16857 Référence CVE CVE-2026-16862 https://www.cve.org/CVERecord?id=CVE-2026-16862 Référence CVE CVE-2026-16864 https://www.cve.org/CVERecord?id=CVE-2026-16864 Référence CVE CVE-2026-16865 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-029845IBMのIBM AIX等の複数製品における配列インデックスの検証に関する脆弱性

IBM AIX 7.2および7.3、ならびにIBM PowerVM VIOS 4.1において、配列インデックスの境界が適切にチェックされていないため、リモートの攻撃者がサービス拒否（DoS）攻撃を引き起こす可能性があります。

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0321Meerdere kwetsbaarheden verholpen in IBM AIX en IBM PowerVM VIOS

IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1 contain a vulnerability due to improper array index boundary checking that allows a remote attacker to cause a denial of service.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
Official vendor articles1 stored document

Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.

  • Security Bulletin: Vulnerabilities in IBM AIX and PowerVM VIOS →Original publisher ↗Searchable text snapshot · Captured 27 Sep 2026IBM Support No results were found for your search query. Tips To return expected results, you can: Reduce the number of search terms. Each term you use focuses the search further. Check your spelling. A single misspelled or incorrectly typed term can change your result. Try substituting synonyms for your original ter
04

Evidence and provenance

Published 19 Aug 2026 · Last source change 20 Aug 2026, 15:57 UTC · CWE-129 · Improper Validation of Array Index

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-23
European sourceENISA EUVD · EUVD-2026-62744
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: added patch: ibm.com/7283858; added remediation: ibm.com/7283858.
    Before
    no authoritative guidance recorded
    After
    patch: ibm.com/7283858 · remediation: ibm.com/7283858
    psirt@us.ibm.com ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    7.2; 7.3; 4.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    7.2; 7.3; 4.1 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
  3. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    psirt@us.ibm.com ↗
  4. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-62744↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-16849 · cve.blacktree.nl