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CVE-2021-47465

17
FAUCET Score

CVE-2021-47465 is a vulnerability in the Linux kernel, specifically affecting the KVM (Kernel-based Virtual Machine) for PowerPC Book3S HV architectures. The issue stems from incorrect stack handling in the idle_kvm_start_guest() function, leading to memory corruption on the emergency stack. With a CVSS score of 5.5 (MEDIUM), this vulnerability has a local attack vector, low attack complexity, and requires low privileges. Its primary impact is a high availability risk, potentially causing system instability or crashes, though confidentiality and integrity are not directly affected. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage for this CVE. It is not listed in CISA's Known Exploited Vulnerabilities Catalog.

Impacted Technologies

VendorProductVersion(s)CPE
>= 5.2, < 5.4.156CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
>= 5.5, < 5.10.76CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
>= 5.11, < 5.14.15CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
5.15CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
5.15CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

5.5MEDIUM

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

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
1.8
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.22%
Probability of exploitation in next 30 days
EPSS Percentile
13.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0022 is in the 58th percentile among its peer group of 15,940 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Patches (3)

redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: kernel
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: kernel-rt
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: kernel

Vendor Advisories (1)

redhatCVE-2021-47465Moderate

kernel: KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()

May 22, 2024

References

git.kernel.org / stable/c/6d077c37c4643394b1bae9682da48164fc147ea8
Patch
git.kernel.org / stable/c/80bbb0bc3a0288442f7fe6fc514f4ee1cb06ccb7
Patch
git.kernel.org / stable/c/9b4416c5095c20e110c82ae602c254099b83b72f
Patch
git.kernel.org / stable/c/fbd724c49bead048ae9fc1a5b7bff2fb3e54f855
Patch