CVE-2021-26932

What it is

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-02-17 02:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:44 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-02-17 02:15 UTC

Last modified

2026-06-17 03:44 UTC

Exploit probability

0.3% · EPSS, next 30 days

Record status

Modified

Affected

• Linux Kernel ≤ 5.10.16
• Fedoraproject Fedora 32
• Fedoraproject Fedora 33
• Debian Linux 9.0
• Netapp Cloud Backup
• Netapp solidfire\, Enterprise Sds \& Hci Storage Node
• Netapp Solidfire \& Hci Management Node
• Netapp Hci Compute Node

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-26932.md and follow it. Check whether this project is affected by CVE-2021-26932. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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