Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-26401

21
FAUCET Score

CVE-2021-26401 describes a medium-severity vulnerability affecting certain AMD CPUs where the LFENCE/JMP mitigation (V2-2) may not adequately address the Spectre variant 2 (CVE-2017-5715) speculative execution side-channel vulnerability. An attacker with local, low-privileged access could, with high attack complexity, potentially achieve high confidentiality impact by bypassing existing mitigations. There is no evidence of active exploitation, publicly available exploit code, or significant community discussion surrounding this vulnerability.

Impacted Technologies

VendorProductVersion(s)CPE
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:amd:athlon_x4_940_firmware:-:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:amd:athlon_x4_950_firmware:-:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:amd:athlon_x4_970_firmware:-:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:amd:athlon_x4_835_firmware:-:*:*:*:*:*:*:*
Range not provided by sourceCPE matchmatch criteria
cpe:2.3:o:amd:athlon_x4_845_firmware:-:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

5.6MEDIUM

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

Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
1.1
Impact Score
4.0
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.29%
Probability of exploitation in next 30 days
EPSS Percentile
21.0%
Percentile rank of EPSS score among Peer Group
As of 2026-07-26
Model: v2026.06.15
This CVE's current EPSS score of 0.0029 is in the 65th percentile among its peer group of 1,297 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 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 0.4 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (5)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6 Extended Lifecycle SupportFixed in: kernel-0:2.6.32-754.49.1.el6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: kernel-rt-0:3.10.0-1160.83.1.rt56.1228.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: kernel-0:3.10.0-1160.83.1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: kernel-rt-0:4.18.0-372.9.1.rt7.166.el8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: kernel-0:4.18.0-372.9.1.el8
View patch

Vendor Advisories (1)

redhatCVE-2021-26401Moderate

hw: cpu: LFENCE/JMP Mitigation Update for CVE-2017-5715

Mar 8, 2022

References

amd.com / en/corporate/product-security/bulletin/amd-sb-1036
Vendor Advisory
openwall.com / lists/oss-security/2022/03/18/2
Mailing ListThird Party Advisory