In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR
maybe_fork_scalars() is called for both BPF_AND and BPF_OR when the
source operand is a constant. When dst has signed range [-1, 0], it
forks the verifier state: the pushed path gets dst = 0, the current
path gets dst = -1.
For BPF_AND this is correct: 0 & K == 0.
For BPF_OR this is wrong: 0 | K == K, not 0.
The pushed path therefore tracks dst as 0 when the runtime value is K,
producing an exploitable verifier/runtime divergence that allows
out-of-bounds map access.
Fix this by passing env->insn_idx (instead of env->insn_idx + 1) to
push_stack(), so the pushed path re-executes the ALU instruction with
dst = 0 and naturally computes the correct result for any opcode.
References
Configurations
Configuration 1 (hide)
|
History
20 May 2026, 15:49
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| References | () https://git.kernel.org/stable/c/342aa1ee995ef5bbf876096dc3a5e51218d76fa4 - Patch | |
| References | () https://git.kernel.org/stable/c/58bd87d0e69204dbd739e4387a1edb0c4b1644e7 - Patch | |
| References | () https://git.kernel.org/stable/c/c845894ebd6fb43226b3118d6b017942550910c5 - Patch | |
| References | () https://git.kernel.org/stable/c/d13281ae7ea8902b21d99d10a2c8caf0bdec0455 - Patch | |
| CWE | CWE-125 | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
27 Apr 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
12 Apr 2026, 06:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-12 06:16
Updated : 2026-05-20 15:49
NVD link : CVE-2026-31413
Mitre link : CVE-2026-31413
CVE.ORG link : CVE-2026-31413
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-125
Out-of-bounds Read