CVE-2026-53362(linux linux kernel)の深刻度・悪用状況・対象バージョン

7.8 重要(CVSS 3.x) 悪用確認済み(CISA KEV) EPSS 取得中…

概要

In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap (datalen = length + fraggap). When fraggap is non-zero, this is not the first skb and transhdrlen is zero. The fraggap bytes carried over from the previous skb are copied just past the fragment headers in the new skb's linear area. The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount, and the copy writes past skb->end into the trailing skb_shared_info. An unprivileged user can trigger this via a UDPv6 socket using MSG_MORE together with MSG_SPLICE_PAGES. The bad accounting was introduced by commit 773ba4fe9104 ("ipv6: avoid partial copy for zc"). Before commit ce650a166335 ("udp6: Fix __ip6_append_data()'s handling of MSG_SPLICE_PAGES"), the negative copy value caused -EINVAL to be returned. That later commit allowed MSG_SPLICE_PAGES to proceed in this case, making the corruption triggerable. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic. Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES case, remove the MSG_SPLICE_PAGES exception from the negative copy check.

実際の攻撃で悪用されています。 CISA KEV への追加日: 2026-08-27。対象製品を使っている場合は最優先で対策してください。
CISA の要求対応: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

影響を受ける製品

ベンダー製品対象バージョン
linuxlinux_kernel≥ 6.0 かつ < 6.1.177
linuxlinux_kernel≥ 6.2 かつ < 6.6.144
linuxlinux_kernel≥ 6.7 かつ < 6.12.95
linuxlinux_kernel≥ 6.13 かつ < 6.18.38
linuxlinux_kernel≥ 6.19 かつ < 7.1.3
siemenssimatic_s7-1500_tm_mfp_firmwareすべて/記載なし

基本情報

公開日
2026-07-04
最終更新
2026-10-15
NVD の状態
Analyzed
弱点の種類
CWE-787 CWE-122

対策の進め方

  1. 上の表で、使っている製品とバージョンが対象か確認します。
  2. ベンダーの公式アドバイザリ(下の参考情報の「Vendor Advisory」「Patch」)で修正版・回避策を確認します。
  3. 悪用が確認されているため、パッチ適用までの間もアクセス制限・侵害の痕跡確認を検討します。
  4. 日本語の情報は JVN iPedia で CVE-2026-53362 を検索 できます。

参考情報

データ出典: NIST NVD、CISA KEV、FIRST EPSS。翻訳は参考情報で、正確性は原文を優先してください。