An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects pointer types that do not define a ptr_limit.
An official patch is available. Apply the patch as soon as possible.
CVSS v4.0 Metrics
Exploitability
Attack VectorLocal
ComplexityHigh
RequirementsPresent
PrivilegesLow
User InteractionNone
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityHigh
IntegrityNone
AvailabilityNone
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Patch StatusOfficial Patch
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | PoC | E: U→P | 1.9 → 4.7 |
| 2026-07-21 | nvd | AV: P→L, PR: H→L, UI: A→N, VC: N→H | 0.0 → 1.9 |
| 2026-07-21 | nvd | patch: Unavailable→Official Patch | 0.0 → 0.0 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| canonical | ubuntu_linux | 14.04 |
| canonical | ubuntu_linux | 16.04 |
| canonical | ubuntu_linux | 18.04 |
| canonical | ubuntu_linux | 20.04 |
| debian | debian_linux | 9.0 |
| fedoraproject | fedora | 32 |
| fedoraproject | fedora | 33 |
| fedoraproject | fedora | 34 |
| linux | linux_kernel | ≤ 5.11.8 |
Published: 2021-03-20
