CVE-2026-53081

In the Linux kernel, the following vulnerability has been resolved: bpf: Enforce regsafe base id consistency for BPF_ADD_CONST scalars When regsafe() compares two scalar registers that both carry BPF_ADD_CONST, check_scalar_ids() maps their full compound id (aka base | BPF_ADD_CONST flag) as one idmap entry. However, it never verifies that the underlying base ids, that is, with the flag stripped are consistent with existing idmap mappings. This allows construction of two verifier states where the old state has R3 = R2 + 10 (both sharing base id A) while the current state has R3 = R4 + 10 (base id C, unrelated to R2). The idmap creates two independent entries: A->B (for R2) and A|flag->C|flag (for R3), without catching that A->C conflicts with A->B. State pruning then incorrectly succeeds. Fix this by additionally verifying base ID mapping consistency whenever BPF_ADD_CONST is set: after mapping the compound ids, also invoke check_ids() on the base IDs (flag bits stripped). This ensures that if A was already mapped to B from comparing the source register, any ADD_CONST derivative must also derive from B, not an unrelated C.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

History

23 Jul 2026, 18:37

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/13c02881e49aac4c82b261faa26db9edf2567231 - () https://git.kernel.org/stable/c/13c02881e49aac4c82b261faa26db9edf2567231 - Patch
References () https://git.kernel.org/stable/c/2f2ec8e7730e21fc9bd49e0de9cdd58213ea24d0 - () https://git.kernel.org/stable/c/2f2ec8e7730e21fc9bd49e0de9cdd58213ea24d0 - Patch
References () https://git.kernel.org/stable/c/691adf738817275368ed56311b7d798d617823a3 - () https://git.kernel.org/stable/c/691adf738817275368ed56311b7d798d617823a3 - Patch
References () https://git.kernel.org/stable/c/7d73c72cccac651acc891377a5e623e4021c6380 - () https://git.kernel.org/stable/c/7d73c72cccac651acc891377a5e623e4021c6380 - Patch
References () https://access.redhat.com/security/cve/CVE-2026-53081 - () https://access.redhat.com/security/cve/CVE-2026-53081 - Third Party Advisory
References () https://bugzilla.redhat.com/show_bug.cgi?id=2492322 - () https://bugzilla.redhat.com/show_bug.cgi?id=2492322 - Third Party Advisory
References () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53081.json - () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53081.json - Third Party Advisory
CWE NVD-CWE-noinfo
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
First Time Linux linux Kernel
Linux

30 Jun 2026, 03:20

Type Values Removed Values Added
References
  • () https://access.redhat.com/security/cve/CVE-2026-53081 -
  • () https://bugzilla.redhat.com/show_bug.cgi?id=2492322 -
  • () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53081.json -
CWE CWE-386

28 Jun 2026, 08:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

24 Jun 2026, 17:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-06-24 17:17

Updated : 2026-07-23 18:37


NVD link : CVE-2026-53081

Mitre link : CVE-2026-53081

CVE.ORG link : CVE-2026-53081


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
NVD-CWE-noinfo CWE-386

Symbolic Name not Mapping to Correct Object