In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-2785-1 linux-4.19 security update
EUVD EUVD EUVD-2021-21206 In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.
Ubuntu USN Ubuntu USN USN-5092-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5092-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5096-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-5115-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-5137-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-5137-2 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 08 Oct 2026 22:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-10-08T21:03:27.477Z

Reserved: 2021-06-10T00:00:00.000Z

Link: CVE-2021-34556

cve-icon Vulnrichment

Updated: 2024-08-04T00:12:50.411Z

cve-icon NVD

Status : Modified

Published: 2021-08-02T05:15:07.663

Modified: 2026-10-08T21:17:35.903

Link: CVE-2021-34556

cve-icon Redhat

Severity : Moderate

Publid Date: 2021-08-01T00:00:00Z

Links: CVE-2021-34556 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses