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UBUNTU-CVE-2021-26401
LFENCE/JMP (mitigation V2-2) may not sufficiently mitigate CVE-2017-5715 on some AMD CPUs.
AI summary snake-internal / snake-template-v1
A weakness called UBUNTU-CVE-2021-26401 was discovered in the affected product.
Severity is Info. Low severity or not yet rated.
What you should do: update the affected software to the latest version. If unsure, ask your IT team or search the vendor's site for "the product UBUNTU-CVE-2021-26401".
UBUNTU-CVE-2021-26401 (the affected product). Severity: Info.
Response plan:
1. Check the vendor advisory for affected versions and the patched release.
2. If a vulnerable version is running in production, schedule maintenance (urgency from KEV/CVSS).
3. If no patch yet, mitigate via WAF rule, disabling the affected feature, etc.
4. Monitor logs / SIEM for known IOC and PoC signatures of this CVE.
PoCs and fix commits: see the 'References' section, MITRE, and NVD.
❓ What is the problem
A weakness (UBUNTU-CVE-2021-26401) in the affected product. A serious software flaw has been identified.
📍 Affected scope
Target versions of the affected product (see vendor advisory). If running in production, identify exposure immediately.
🔥 Severity
Severity: Info. Low severity or not yet rated.
🔧 How to fix
Update to the patched release as listed in the vendor advisory.
🛡️ Workaround
If a patch is not yet available, consider disabling the affected feature, applying WAF rules, blocking via network ACLs, or isolating the vulnerable version.
🔍 Detection
Check version information, scan dependencies via SBOM, and monitor SIEM for IOC and PoC signatures related to this CVE.
Affected packages
Ubuntu:Pro:14.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1117.123"}]}]
Ubuntu:Pro:14.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1138.151~14.04.1"}]}]
Ubuntu:Pro:14.04:LTS
linux-lts-xenial
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-239.273~14.04.1"}]}]
Ubuntu:Pro:14.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:16.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-239.273"}]}]
Ubuntu:Pro:16.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1155.170"}]}]
Ubuntu:Pro:16.04:LTS
linux-aws-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1128.137~16.04.1"}]}]
Ubuntu:Pro:16.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1138.151~16.04.1"}]}]
Ubuntu:Pro:16.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1122.136~16.04.1"}]}]
Ubuntu:Pro:16.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-177.186~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:16.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1118.128"}]}]
Ubuntu:Pro:16.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1093.102~16.04.1"}]}]
Ubuntu:Pro:FIPS:16.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-177.186"}]}]
Ubuntu:18.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1128.137"}]}]
Ubuntu:18.04:LTS
linux-aws-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1075.80~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-azure-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1138.151"}]}]
Ubuntu:18.04:LTS
linux-azure-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1078.81~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-dell300x
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1042.47"}]}]
Ubuntu:18.04:LTS
linux-gcp-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1122.136"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.78~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-gke-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1071.76~18.04.3"}]}]
Ubuntu:18.04:LTS
linux-gkeop-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1040.41~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-hwe-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-110.124~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-ibm-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1021.23~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1114.117"}]}]
Ubuntu:18.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1093.102"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1071.77~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-raspi-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1060.68~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1109.116"}]}]
Ubuntu:18.04:LTS
linux-snapdragon
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1127.136"}]}]
Ubuntu:18.04:LTS
linux-aws-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-aws-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gke-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oem
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2067.70"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2049.53"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1085.94"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2032.35"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-110.124"}]}]
Ubuntu:20.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.78"}]}]
Ubuntu:20.04:LTS
linux-aws-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1023.25~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1078.81"}]}]
Ubuntu:20.04:LTS
linux-azure-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1023.27~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-bluefield
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1040.44"}]}]
Ubuntu:20.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.78"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1025.30~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-gke
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1071.76"}]}]
Ubuntu:20.04:LTS
linux-gkeop
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1040.41"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-41.46~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-ibm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1021.23"}]}]
Ubuntu:20.04:LTS
linux-intel-iotg-5.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.0-1008.11~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-iot
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1004.6"}]}]
Ubuntu:20.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1063.66"}]}]
Ubuntu:20.04:LTS
linux-oem-5.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.0-1033.36"}]}]
Ubuntu:20.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1071.77"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1028.33~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-raspi
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1060.68"}]}]
Ubuntu:20.04:LTS
linux-aws-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-aws-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:20.04:LTS
linux-azure-fde-5.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-intel-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.10
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.6
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.78+fips1"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1078.81+fips1"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1049.55"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.78+fips1"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-intel-iot-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-raspi-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:26.04
linux-nvidia
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- advisory https://ubuntu.com/security/notices/USN-5415-1
- advisory https://ubuntu.com/security/notices/USN-5417-1
- advisory https://ubuntu.com/security/notices/USN-5418-1
- advisory https://ubuntu.com/security/notices/USN-6001-1
- advisory https://ubuntu.com/security/notices/USN-6013-1
- advisory https://ubuntu.com/security/notices/USN-6014-1
- report https://ubuntu.com/security/CVE-2021-26401
- report http://www.openwall.com/lists/oss-security/2022/03/18/2
- report https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1036
- report https://www.cve.org/CVERecord?id=CVE-2021-26401