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Full vulnerability report · 2026
CVE-2026-76729High confidence

Authenticated Format String Vulnerability allows Memory Corruption in HPE Networking Instant ON API Endpoint

Hewlett Packard Enterprise (HPE) · Instant ON

6.6MediumCVSS 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 0.42% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Hewlett Packard Enterprise (HPE) Instant ON 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.

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
HPESBNW05150 · CSAF 2.0 · revision 1 · finalHPE NetworkingAuthenticated Format String Vulnerability allows Memory Corruption in HPE Networking Instant ON API Endpoint
1 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • HPE Networking Instant ON APs
Summary
A format string vulnerability in the API endpoint of HPE Networking Instant ON APs could allow an authenticated remote attacker with high privileges to cause memory corruption with a modified input. Successful exploitation could allow an attacker to provoke a denial-of-service condition or remote code execution in the affected system function.
Remediation
In order to address the vulnerabilities described in the Details Section, HPE Networking recommends upgrading the HPE Networking Instant ON APs software to the following version (as applicable): - Instant ON 3.4.2.0 and above. Software versions with resolution/fixes for the disclosed vulnerabilities will be applied to the affected APs automatically by the Instant On cloud management portal. Product software versions that have reached End of Maintenance (EoM) are presumed to be affected by the vulnerabilities unless explicitly stated otherwise, and are not completely addressed by this security advisory. For deployments running software versions that are past End of Support (EoST), HPE Networking has not assessed exposure to the vulnerabilities referenced in this advisory. As a result, such installations should be considered potentially impacted by the listed CVE. Customers are strongly encouraged to upgrade to a supported software release to ensure proper evaluation and remediation.
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-2026-89348

No EUVD known-exploited evidence

A format string vulnerability in the API endpoint of HPE Networking Instant ON APs could allow an authenticated remote attacker with high privileges to cause memory corruption with a modified input. Successful exploitation could allow an attacker to provoke a denial-of-service condition or remote code execution in the affected system function.

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
6.6 · 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

A format string vulnerability in the API endpoint of HPE Networking Instant ON APs could allow an authenticated remote attacker with high privileges to cause memory corruption with a modified input. Successful exploitation could allow an attacker to provoke a denial-of-service condition or remote code execution in the affected system function.

What

A format string vulnerability in the API endpoint of HPE Networking Instant ON APs could allow an authenticated remote attacker with high privileges to cause memory corruption with a modified input. Successful exploitation could allow an attacker to provoke a denial-of-service condition or remote code execution in the affected system function.

Why

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

What

A format string vulnerability in the API endpoint of HPE Networking Instant ON APs could allow an authenticated remote attacker with high privileges to cause memory corruption with a modified input. Successful exploitation could allow an attacker to provoke a denial-of-service condition or remote code execution in the affected system function.

Why

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.

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
a network path → Use of Externally-Controlled Format String → execute code or commands in the affected security context
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
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-134 ↗

CWE-134: Use of Externally-Controlled Format String. The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

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

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

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-134
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-89348Official EUVD mapping

A format string vulnerability in the API endpoint of HPE Networking Instant ON APs could allow an authenticated remote attacker with high privileges to cause memory corruption with a modified input. Successful exploitation could allow an attacker to provoke a denial-of-service condition or remote code execution in the affected system function.

Official EUVD record ↗
INCIBE-CERT · Spanish · multiples-vulnerabilidades-en-instant-aps-de-hpe-networkingMúltiples vulnerabilidades en Instant On APs de HPE Networking

HPE Networking ha publicado 18 vulnerabilidades: 5 de severidad crítica, 3 de severidad alta, 7 de severidad media y 3 de severidad baja que, en caso de ser explotadas, podrían permitir eludir controles de acceso, ejecutar código o comandos con privilegios elevados, escalar privilegios, realizar solicitudes desde el servidor (SSRF), acceder a información sensible o provocar una denegación de servicio (DoS).

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1238Multiples vulnérabilités dans HPE Aruba Networking Instant On

De multiples vulnérabilités ont été découvertes dans HPE Aruba Networking Instant On. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une élévation de privilèges et un déni de service à distance.

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
HPE Networking Instant ON APs
Fixed
HPE Networking Instant ON APs
Action
In order to address the vulnerabilities described in the Details Section, HPE Networking recommends upgrading the HPE Networking Instant ON APs software to the following version (as applicable): - Instant ON 3.4.2.0 and above. Software versions with resolution/fixes for the disclosed vulnerabilities will be applied to the affected APs automatically by the Instant On cloud management portal. Product software versions that have reached End of Maintenance (EoM) are presumed to be affected by the vulnerabilities unless explicitly stated otherwise, and are not completely addressed by this security advisory. For deployments running software versions that are past End of Support (EoST), HPE Networking has not assessed exposure to the vulnerabilities referenced in this advisory. As a result, such installations should be considered potentially impacted by the listed CVE. Customers are strongly encouraged to upgrade to a supported software release to ensure proper evaluation and remediation.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 29 Sept 2026 · Last source change 1 Oct 2026, 03:55 UTC · CWE-134 · Use of Externally-Controlled Format String

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 2026-09-30
European sourceENISA EUVD · EUVD-2026-89348
Product sourceVendor CSAF · HPE Networking
Remediation sourceVendor CSAF · HPE Networking
CWE sourceCISA ADP
NVD statusNVD awaiting enrichment

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: removed remediation: csaf.arubanetworking.hpe.com.
    Before
    remediation: csaf.arubanetworking.hpe.com
    After
    no authoritative guidance recorded
    CNA ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    Instant ON: 0.0.0.0 ≤ 3.4.1.0 · Fixed: In order to address the vulnerabilities described in the Details Section, HPE Networking recommends upgrading the HPE Networking Instant ON APs software to the following version (as applicable): - Instant ON 3.4.2.0 and above. Software versions with resolution/fixes for the disclosed vulnerabilities will be applied to the affected APs automatically by the Instant On cloud management portal. Product software versions that have reached End of Maintenance (EoM) are presumed to be affected by the vulnerabilities unless explicitly stated otherwise, and are not completely addressed by this security advisory. For deployments running software versions that are past End of Support (EoST), HPE Networking has not assessed exposure to the vulnerabilities referenced in this advisory. As a result, such installations should be considered potentially impacted by the listed CVE. Customers are strongly encouraged to upgrade to a supported software release to ensure proper evaluation and remediation.
    After
    Instant ON: 0.0.0.0 ≤ 3.4.1.0 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  3. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    CNA ↗
  4. Vendor guidanceAuthoritative vendor guidance changed: removed remediation: csaf.arubanetworking.hpe.com.
    Before
    remediation: csaf.arubanetworking.hpe.com
    After
    no authoritative guidance recorded
    CNA ↗
  5. Affected versionsThe structured affected or fixed version information changed.
    Before
    Instant ON: 0.0.0.0 ≤ 3.4.1.0 · Fixed: In order to address the vulnerabilities described in the Details Section, HPE Networking recommends upgrading the HPE Networking Instant ON APs software to the following version (as applicable): - Instant ON 3.4.2.0 and above. Software versions with resolution/fixes for the disclosed vulnerabilities will be applied to the affected APs automatically by the Instant On cloud management portal. Product software versions that have reached End of Maintenance (EoM) are presumed to be affected by the vulnerabilities unless explicitly stated otherwise, and are not completely addressed by this security advisory. For deployments running software versions that are past End of Support (EoST), HPE Networking has not assessed exposure to the vulnerabilities referenced in this advisory. As a result, such installations should be considered potentially impacted by the listed CVE. Customers are strongly encouraged to upgrade to a supported software release to ensure proper evaluation and remediation.
    After
    Instant ON: 0.0.0.0 ≤ 3.4.1.0 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  6. Remediation statusRemediation status changed from Patch available to Awaiting fix.
    Before
    Patch available
    After
    Awaiting fix
    CNA ↗
  7. ENISA EUVD mappingEUVD-2026-89348 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-89348"}
    ENISA EUVD ↗
  8. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
  9. Affected versionsThe structured affected or fixed version information changed.
    Before
    Instant ON: 0.0.0.0 ≤ 3.4.1.0 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Instant ON: 0.0.0.0 ≤ 3.4.1.0 · Fixed: In order to address the vulnerabilities described in the Details Section, HPE Networking recommends upgrading the HPE Networking Instant ON APs software to the following version (as applicable): - Instant ON 3.4.2.0 and above. Software versions with resolution/fixes for the disclosed vulnerabilities will be applied to the affected APs automatically by the Instant On cloud management portal. Product software versions that have reached End of Maintenance (EoM) are presumed to be affected by the vulnerabilities unless explicitly stated otherwise, and are not completely addressed by this security advisory. For deployments running software versions that are past End of Support (EoST), HPE Networking has not assessed exposure to the vulnerabilities referenced in this advisory. As a result, such installations should be considered potentially impacted by the listed CVE. Customers are strongly encouraged to upgrade to a supported software release to ensure proper evaluation and remediation.
    HPE Networking ↗
  10. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    HPE Networking ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2026-89348↗HPE Networking security advisory↗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-2026-76729 · cve.blacktree.nl