Xen VMX VMEntry resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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4.9$0-$5k0.00

Summaryinfo

A vulnerability was found in Xen. It has been classified as problematic. This affects an unknown part of the component VMX VMEntry. This manipulation causes resource consumption. This vulnerability appears as CVE-2026-79611. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability has been found in Xen (unknown version) and classified as problematic. Affected by this vulnerability is an unknown code block of the component VMX VMEntry. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

For XSA-308 logic was introduced, as VMX VMEntry checks do not like the exact combination of state which occurs when #DB in intercepted, Single Stepping is active, and blocked by STI/MovSS is active, despite this being a legitimate state to be in. The resulting VMEntry failure is fatal to the guest. Sadly there is another special sub-case of the above, with branch tracing enabled. In that case the prior adjustment would still cause a VMentry failure, as before fatal to the guest.

The advisory is shared at xenbits.xenproject.org. This vulnerability is known as CVE-2026-79611 since 08/25/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are necessary for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/01/2026). MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 374779 (SUSE SLED15: xen / xen-devel / xen-libs / xen-tools / xen-tools-domU / etc (SUSE-SU-2026:4942-1)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (374779). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.9
VulDB Temp Score: 4.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 374779
Nessus Name: SUSE SLED15: xen / xen-devel / xen-libs / xen-tools / xen-tools-domU / etc (SUSE-SU-2026:4942-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

08/25/2026 CVE reserved
10/13/2026 +49 days Advisory disclosed
10/13/2026 +0 days VulDB entry created
11/01/2026 +19 days VulDB entry last update

Sourcesinfo

Advisory: xenbits.xenproject.org
Status: Confirmed

CNA: XEN
CVE: CVE-2026-79611 (🔒)

GCVE (CVE): GCVE-0-2026-79611
GCVE (VulDB): GCVE-100-417793

Entryinfo

Created: 10/13/2026 18:31
Updated: 11/01/2026 18:06
Changes: 10/13/2026 18:31 (51), 11/01/2026 18:06 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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