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CVE-2021-28951

20
FAUCET Score

CVE-2021-28951 is a denial-of-service vulnerability affecting the Linux kernel, specifically versions up to 5.11.8, including products from Fedora Project and NetApp. The flaw, located in fs/io_uring.c, allows an authenticated local attacker to trigger a deadlock condition. With a CVSS score of 5.5 (Medium), this vulnerability has a low attack complexity and requires local privileges, leading to high availability impact. There is no evidence of active exploitation, publicly available exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
<= 5.11.8CPE matchmatch criteria
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
32CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
34CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:netapp:a250_firmware:-:*:*:*:*:*:*:*

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
0.28%
Probability of exploitation in next 30 days
EPSS Percentile
20.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-26
Model: v2026.06.15
This CVE's current EPSS score of 0.0028 is in the 76th percentile among its peer group of 15,938 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

Patch Available

Vendor Patches (2)

microsoftpatch availablevia msrc
Product: 16920-16823Fixed in: 5.10.78.1-1
microsoftpatch availablevia msrc
Product: cbl2 kernel 5.10.78.1-1 on CBL Mariner 2.0Fixed in: 5.10.78.1-1

Vendor Advisories (2)

microsoft2021-Mar/CVE-2021-28951Moderate

An issue was discovered in fs/io_uring.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (deadlock) because exit may be waiting to park a SQPOLL thread but concurrently that SQPOLL thread is waiting for a signal to start aka CID-3ebba796fa25.

Mar 9, 2021
redhatCVE-2021-28951Moderate

kernel: DoS because of deadlock in fs/io_uring.c

Mar 4, 2021

References

git.kernel.org / pub/scm/linux/kernel/git/stable/linux.git/commit
PatchVendor Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/4VCKIOXCOZGXBEZMO5LGGV5MWCHO6FT3
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/PTRNPQTZ4GVS46SZ4OBXY5YDOGVPSTGQ
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/T2S3I4SLRNRUQDOFYUS6IUAZMQNMPNLG
security.netapp.com / advisory/ntap-20210430-0003
Third Party Advisory