HOMEVULNERABILITIESCVE-2026-23557
MEDIUM

CVE-2026-23557

Published: May 19, 2026· Updated: May 19, 2026

6.5
CVSS v3.1
EPSS:0.01%probability of exploitation in 30 daysPercentile:1.6th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-23557 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeChanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Affected Vendors & Products

xen1 product
xen
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://xenbits.xenproject.org/xsa/advisory-484.html
PATCHhttp://www.openwall.com/lists/oss-security/2026/04/28/11
PATCHhttp://xenbits.xen.org/xsa/advisory-484.html

All References (3)

→
https://xenbits.xenproject.org/xsa/advisory-484.htmlPatch · Vendor Advisory
→
http://www.openwall.com/lists/oss-security/2026/04/28/11Mailing List · Patch · Third Party Advisory
→
http://xenbits.xen.org/xsa/advisory-484.htmlPatch · Vendor Advisory

Quick Facts

CVE IDCVE-2026-23557
CVSS Score6.5 / 10
SeverityMEDIUM
CISA KEVNo
EPSS (30d)0.01%
Affected1 vendor
PublishedMay 19, 2026

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-23557 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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