Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.56% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-76721High confidence
Unauthenticated Buffer Overflow Vulnerability leads to Remote Code Execution in HPE Networking Instant ON APs
Hewlett Packard Enterprise (HPE) · Instant ON
9.8CriticalCVSS 3.1
Within 72 hours
Patch availableCritical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
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
- Confirm that the asset runs Hewlett Packard Enterprise (HPE) Instant ON and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Direct vendor intelligence
1 currentAuthoritative 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.
HPESBNW05150 · CSAF 2.0 · revision 1 · finalHPE NetworkingUnauthenticated Buffer Overflow Vulnerability leads to Remote Code Execution in HPE Networking Instant ON APs
The vendor explicitly identifies these products as affected by this CVE.
- HPE Networking Instant ON APs
- Summary
- Buffer overflow vulnerability exists in the affected interface of HPE Networking Instant ON that could allow an unauthenticated remote attacker to run arbitrary code on the underlying host. Successful exploitation could allow an attacker to execute arbitrary code as a privileged user on the underlying operating system.
- 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.
Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.
Patch available01
What, why and how
Buffer overflow vulnerability exists in the affected interface of HPE Networking Instant ON that could allow an unauthenticated remote attacker to run arbitrary code on the underlying host. Successful exploitation could allow an attacker to execute arbitrary code as a privileged user on the underlying operating system.
What
Buffer overflow vulnerability exists in the affected interface of HPE Networking Instant ON that could allow an unauthenticated remote attacker to run arbitrary code on the underlying host. Successful exploitation could allow an attacker to execute arbitrary code as a privileged user on the underlying operating system.
Why
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
What
Buffer overflow vulnerability exists in the affected interface of HPE Networking Instant ON that could allow an unauthenticated remote attacker to run arbitrary code on the underlying host. Successful exploitation could allow an attacker to execute arbitrary code as a privileged user on the underlying operating system.
Why
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → Improper Restriction of Operations within the Bounds of a Memory Buffer → execute code or commands in the affected security context
- Attack surface
- Network
- 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-119 ↗
CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer. The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
- 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:L/PR:N/UI:N/S:U/C:H/I:H/A:HCommon 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.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.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.
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
- 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 30 Sept 2026, 20:11 UTC · CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-30
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-89340
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
View recent updates ↗What changed after publication
- Vendor guidanceAuthoritative vendor guidance changed: removed remediation: csaf.arubanetworking.hpe.com.CNA ↗
- Before
- remediation: csaf.arubanetworking.hpe.com
- After
- no authoritative guidance recorded
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- 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.
- Remediation statusRemediation status changed from Patch available to Awaiting fix.CNA ↗
- Before
- Patch available
- After
- Awaiting fix
- ENISA EUVD mappingEUVD-2026-89340 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-89340"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
- Affected versionsThe structured affected or fixed version information changed.HPE Networking ↗
- 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.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.HPE Networking ↗
- Before
- Awaiting fix
- After
- Patch available
CVE published
Fixed release recorded from official guidance
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.