bpf: Enforce regsafe base id consistency for BPF_ADD_CONST scalars

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-53081
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-24 17:17:22 UTC
Updated2026-07-23 18:37:50 UTC
DescriptionIn 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.

Risk And Classification

Primary CVSS: v3.1 6.4 MEDIUM from ADP

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

EPSS: 0.001160000 probability, percentile 0.019210000 (date 2026-07-17)

Problem Types: NVD-CWE-noinfo | CWE-386 | CWE-386 Symbolic Name not Mapping to Correct Object

VersionSourceTypeScoreSeverityVector
3.1ADPCVSS6.4MEDIUMCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary6.4MEDIUMCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 98d7ca374ba4b39e7535613d40e159f09ca14da2 13c02881e49aac4c82b261faa26db9edf2567231 git Not specified
CNA Linux Linux affected 98d7ca374ba4b39e7535613d40e159f09ca14da2 691adf738817275368ed56311b7d798d617823a3 git Not specified
CNA Linux Linux affected 98d7ca374ba4b39e7535613d40e159f09ca14da2 7d73c72cccac651acc891377a5e623e4021c6380 git Not specified
CNA Linux Linux affected 98d7ca374ba4b39e7535613d40e159f09ca14da2 2f2ec8e7730e21fc9bd49e0de9cdd58213ea24d0 git Not specified
CNA Linux Linux affected 6.11 Not specified
CNA Linux Linux unaffected 6.11 semver Not specified
CNA Linux Linux unaffected 6.12.91 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.33 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.10 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified
ADP Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 6 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified

References

ReferenceSourceLinkTags
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com Third Party Advisory
access.redhat.com/security/cve/CVE-2026-53081 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com Third Party Advisory
git.kernel.org/stable/c/691adf738817275368ed56311b7d798d617823a3 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53081.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com Third Party Advisory
git.kernel.org/stable/c/2f2ec8e7730e21fc9bd49e0de9cdd58213ea24d0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/13c02881e49aac4c82b261faa26db9edf2567231 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/7d73c72cccac651acc891377a5e623e4021c6380 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
ADP2026-06-24T00:00:00.000ZReported to Red Hat.
ADP2026-06-24T00:00:00.000ZMade public.

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