[UPDATE] [medium] Xen and Citrix Systems XenServer: Multiple vulnerabilities

mediumCVE-2026-23554 CVE-2026-23555

A local attacker can exploit multiple vulnerabilities in Xen and Citrix Systems XenServer to escalate privileges, cause a Denial-of-Service condition, or disclose confidential information.

CSIRTS triage

Privilege escalation Denial of service Information disclosure

What: Multiple vulnerabilities in Xen and Citrix XenServer allow privilege escalation, denial of service, and confidential information disclosure.
Who is affected: Deployments of Xen and Citrix XenServer with local access are affected.
Urgency: Medium priority; local access required but enables privilege escalation and data theft.
Action: Apply patches for CVE-2026-23554 and CVE-2026-23555 for both Xen and XenServer.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: medium
Published: 2026-08-10
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0760

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-235540.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-235550.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 8% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-23554	coverage & exploitation status	NVD · CVE.org
CVE-2026-23555	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownDSA-6424-1 xen - security updatedebian