Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.26% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-23822High confidence
Unauthenticated XML External Entity Injection in AOS-8 Instant allows Denial of Service
Hewlett Packard Enterprise (HPE) · ArubaOS (AOS)
5.3MediumCVSS 3.1
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, 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) ArubaOS (AOS) 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.
HPESBNW05049 · CSAF 2.0 · revision 1 · finalHPE NetworkingUnauthenticated XML External Entity Injection in AOS-8 Instant allows Denial of Service
The vendor explicitly identifies these products as affected by this CVE.
- AOS-8
- Summary
- A vulnerability in the XML handling component of AOS-8 DHCP services could allow an unauthenticated remote attacker to trigger a denial-of-service condition. Successful exploitation could allow an attacker to cause excessive resource consumption upon user interaction, leading to service disruption or reduced availability of the affected system.
- Remediation
- To address this vulnerability, upgrade HPE Aruba Networking AOS-8 Instant software to one of the following versions (as applicable): - AOS-8 Instant 8.13.x.x: 8.13.1.2 and above - AOS-8 Instant 8.12.x.x: 8.12.0.7 and above - AOS-8 Instant 8.10.x.x: 8.10.0.22 and above
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
A vulnerability in the XML handling component of AOS-8 DHCP services could allow an unauthenticated remote attacker to trigger a denial-of-service condition. Successful exploitation could allow an attacker to cause excessive resource consumption upon user interaction, leading to service disruption or reduced availability of the affected system. NOTE: This vulnerability only impacts Access Points running AOS Instant 8.x.x.x
What
A vulnerability in the XML handling component of AOS-8 DHCP services could allow an unauthenticated remote attacker to trigger a denial-of-service condition. Successful exploitation could allow an attacker to cause excessive resource consumption upon user interaction, leading to service disruption or reduced availability of the affected system. NOTE: This vulnerability only impacts Access Points running AOS Instant 8.x.x.x
Why
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
How
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
A vulnerability in the XML handling component of AOS-8 DHCP services could allow an unauthenticated remote attacker to trigger a denial-of-service condition. Successful exploitation could allow an attacker to cause excessive resource consumption upon user interaction, leading to service disruption or reduced availability of the affected system. NOTE: This vulnerability only impacts Access Points running AOS Instant 8.x.x.x
Why
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
How
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
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 Recursive Entity References in DTDs ('XML Entity Expansion') → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Required interaction required
- 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-776 ↗
CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion'). The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
- 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:N/UI:R/S:U/C:N/I:N/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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.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.AHighAvailability impact: A successful attack can cause a major 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.
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
- AOS-8
- Fixed
- AOS-8
- Action
- To address this vulnerability, upgrade HPE Aruba Networking AOS-8 Instant software to one of the following versions (as applicable): - AOS-8 Instant 8.13.x.x: 8.13.1.2 and above - AOS-8 Instant 8.12.x.x: 8.12.0.7 and above - AOS-8 Instant 8.10.x.x: 8.10.0.22 and above
- 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 12 May 2026 · Last source change 12 May 2026, 19:25 UTC · CWE-776 · Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-29738
Product sourceVendor CSAF · HPE Networking
Remediation sourceVendor CSAF · HPE Networking
CWE sourceCISA ADP
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.HPE Networking ↗
- Before
- 8.13.0.0 ≤ 8.13.1.1; 8.12.0.0 ≤ 8.12.0.6; 8.10.0.0 ≤ 8.10.0.21 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- 8.13.0.0 ≤ 8.13.1.1; 8.12.0.0 ≤ 8.12.0.6; 8.10.0.0 ≤ 8.10.0.21 · Fixed: To address this vulnerability, upgrade HPE Aruba Networking AOS-8 Instant software to one of the following versions (as applicable): - AOS-8 Instant 8.13.x.x: 8.13.1.2 and above - AOS-8 Instant 8.12.x.x: 8.12.0.7 and above - AOS-8 Instant 8.10.x.x: 8.10.0.22 and above
- 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.