GHSA-x8qw-46ww-c957 · 深刻度： medium — In the Linux kernel, the following vulnerability has been resolved: x86/vmscape: Add conditional...
In the Linux kernel, the following vulnerability has been resolved: x86/vmscape: Add conditional IBPB mitigation VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit. Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB. This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace. The intent is to integrate and optimize these cases post-embargo. [ dhansen: elaborate on suboptimal IBPB solution ]
総合評価: CVE-2025-40300 は低リスク（30.9/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.33%、25 パーセンタイル） 推奨対応: 悪用情報と EPSS の推移を監視し、必要に応じて優先度を見直してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.04% | 0.33% | +0.29% |
| 2 | 2026-01-17 | 0.08% | 0.04% | -0.04% |
| 3 | 2025-10-17 | — | 0.08% | — |
EPSS の全履歴 （全 4 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
GHSA-x8qw-46ww-c957 · 深刻度： medium — In the Linux kernel, the following vulnerability has been resolved: x86/vmscape: Add conditional...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-40300 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2025-40300 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-40300 |
suse
|
medium | — | https://www.suse.com/security/cve/CVE-2025-40300/ |
ubuntu
|
high | CVE-2025-40300 high priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, released 211, ignored 161, not-affected 17, needs-triage 4, needed 3, pending 1. | https://ubuntu.com/security/CVE-2025-40300 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| linux | linux_kernel | >= 3.16.57, < 3.17 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.4.168, < 4.5 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.16, < 5.10.244 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 5.11, < 5.15.193 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 5.16, < 6.1.152 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.2, < 6.6.106 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.7, < 6.12.47 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.13, < 6.16.7 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | 6.17 | cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* |
| linux | linux_kernel | 6.17 | cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* |
| linux | linux_kernel | 6.17 | cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* |
| linux | linux_kernel | 6.17 | cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* |
| linux | linux_kernel | 6.17 | cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* |
| debian | debian_linux | 11.0 | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |