A vulnerability was found in the Linux kernel's EBPF verifier when handling internal data structures. Internal memory locations could be returned to userspace. A local attacker with the permissions to insert eBPF code to the kernel can use this to leak internal kernel memory details defeating some of the exploit mitigations in place for the kernel.
CVE-2021-4159
CVSS base score
4.4 (v3.1)
Severity
MEDIUM
Attack vector
Local
Weakness
CWE-202
Last modified
November 2, 2026
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Affected products
linux linux kernel
redhat enterprise linux
debian debian linux
References
- access.redhat.com Third Party Advisory
- bugzilla.redhat.com Issue Tracking
- git.kernel.org Mailing List, Patch, Vendor Advisory
- lists.debian.org Mailing List, Third Party Advisory
- security-tracker.debian.org Third Party Advisory
- access.redhat.com Third Party Advisory
- bugzilla.redhat.com Issue Tracking
- git.kernel.org Mailing List, Patch, Vendor Advisory
- lists.debian.org Mailing List, Third Party Advisory
- security-tracker.debian.org Third Party Advisory