An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting 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-10d2bb2e6b1d.
An official patch is available. Apply the patch as soon as possible.
CVSS v4.0 Metrics
Exploitability
Attack VectorLocal
ComplexityLow
RequirementsPresent
PrivilegesHigh
User InteractionNone
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityHigh
IntegrityNone
AvailabilityHigh
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 | 1.7 → 4.6 |
| 2026-07-21 | nvd | AV: P→L, AC: H→L, UI: A→N, VC: N→H, VA: N→H | 0.0 → 1.7 |
| 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
