Xen Xenstored assert denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.0$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Xen. This issue affects the function assert of the component Xenstored. The manipulation leads to denial of service. This vulnerability is listed as CVE-2026-23557. There is no available exploit. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Xen (version now known). It has been rated as problematic. This issue affects the function assert of the component Xenstored. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering. In case xenstored was built with NDEBUG #defined nothing bad will happen, as assert() is doing nothing in this case. Note that the default is not to define NDEBUG for xenstored builds even in release builds of Xen.

The weakness was presented by Andrii Sultanov. It is possible to read the advisory at xenbits.xenproject.org. The identification of this vulnerability is CVE-2026-23557 since 01/14/2026. Technical details of the vulnerability are known, but there is no available exploit.

Applying a patch is able to eliminate this problem.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.1
VulDB Meta Temp Score: 6.0

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 6.5
ADP CISA Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/14/2026 CVE reserved
05/19/2026 +124 days Advisory disclosed
05/19/2026 +0 days VulDB entry created
05/23/2026 +4 days VulDB entry last update

Sourcesinfo

Advisory: xenbits.xenproject.org
Researcher: Andrii Sultanov
Status: Confirmed

CVE: CVE-2026-23557 (🔒)
GCVE (CVE): GCVE-0-2026-23557
GCVE (VulDB): GCVE-100-364643

Entryinfo

Created: 05/19/2026 15:48
Updated: 05/23/2026 11:52
Changes: 05/19/2026 15:48 (55), 05/23/2026 11:52 (11)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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