VulnerabilityPublished 28 Jul 2026Updated 17 Oct 2026

CVE-2026-62432: Xen · The EVTCHNOP_expand_array hypercall checks for whether FIFO event channels are enabled, but without holding the correct lock

Affects xenSource GCVE Database

Not known to be exploited · CVSS 7.3 High.

Data as of 27 Oct 2026, 05:11 UTC

CVSS 3.1 base score

7.3High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-92f9-q54w-fxm8

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10xen`pkg:deb/ubuntu/xen?arch=source&distro=stonking`Other threats	Affected =4.20.2+7-g1badcf5035-2build2 =4.20.2+37-g61ff35323e-1ubuntu1 =4.20.3+127-gc42374a105-1	Fixed in–
Ubuntu 26.04 LTSxen`pkg:deb/ubuntu/xen?arch=source&distro=resolute`Other threats	Affected =4.20.0+68-g35cb38b222-1 =4.20.2+7-g1badcf5035-2 =4.20.2+7-g1badcf5035-2build2	Fixed in–
Ubuntu 24.04 LTSxen`pkg:deb/ubuntu/xen?arch=source&distro=noble`Other threats	Affected 4.17.2-1 – 4.17.3+10-g091466ba55-1.1ubuntu3 7 affected builds	Fixed in–
Ubuntu 22.04 LTSxen`pkg:deb/ubuntu/xen?arch=source&distro=jammy`Other threats	Affected =4.11.4+24-gddaaccbbab-1ubuntu2 =4.16.0-1~ubuntu2 =4.16.0-1~ubuntu2.1	Fixed in–
Ubuntu 20.04 LTSxen`pkg:deb/ubuntu/xen?arch=source&distro=focal`Other threats	Affected 4.9.2-0ubuntu2 – 4.11.3+24-g14b62ab3e5-1ubuntu2.3 7 affected builds	Fixed in–
Ubuntu 18.04 LTSxen`pkg:deb/ubuntu/xen?arch=source&distro=bionic`Other threats	Affected =4.9.0-0ubuntu3 =4.9.0-0ubuntu4 =4.9.2-0ubuntu1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until a patch is available, users should monitor vendor advisories for updates and consider mitigating exposure by limiting access to the vulnerable hypercall if possible.

Description

CVE-2026-62432 is a vulnerability in the EVTCHNOP_expand_array hypercall where it checks for FIFO event channels without holding the correct lock. This can race with the EVTCHNOP_reset operation, potentially causing a NULL pointer dereference. The issue is classified as a high severity race condition vulnerability.

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Architecture and Design
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Architecture and Design
Use thread-safe capabilities such as the data access abstraction in Spring.
Architecture and Design
Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
Leveraging Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Jul 2026, 11:22 UTC

WeaknessesCWE-362

Technical details

References

Community reviews

Related threats