CVE-2026-46300: net: skbuff: preserve shared-frag marker during coalescing
Description
In the Linux kernel, the following vulnerability has been resolved: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned or page-cache-backed frags, but the shared-frag marker is currently lost. That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags. Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors.
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Status incidents that name it
- · Minor · names this CVE
“…We have completed our investigation and response to the "DirtyFrag" (CVE-2026-43500, CVE-2026-43284) and "Fragnesia" (CVE-2026-46300) vulnerabilities. We have published documentation articles with detailed guidance on available mitigations and…”
- · Minor · names this CVE
“…We have completed our investigation and response to the "DirtyFrag" (CVE-2026-43500, CVE-2026-43284) and "Fragnesia" (CVE-2026-46300) vulnerabilities. We have published documentation articles with detailed guidance on available mitigations and…”
Affected vendors and products
Linux: LinuxRed Hat: NVIDIA for RHEL 10Red Hat: Red Hat Enterprise Linux 10Red Hat: Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat: Red Hat Enterprise Linux 6Red Hat: Red Hat Enterprise Linux 7Red Hat: Red Hat Enterprise Linux 8Red Hat: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportRed Hat: Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnRed Hat: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRed Hat: Red Hat Enterprise Linux 8.6 Telecommunications Update ServiceRed Hat: Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionsRed Hat: Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRed Hat: Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRed Hat: Red Hat Enterprise Linux 9Red Hat: Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsRed Hat: Red Hat Enterprise Linux 9.2 Update Services for SAP SolutionsRed Hat: Red Hat Enterprise Linux 9.4 Extended Update SupportRed Hat: Red Hat Enterprise Linux 9.4 Update Services for SAP SolutionsRed Hat: Red Hat Enterprise Linux 9.6 Extended Update SupportRed Hat: Red Hat OpenShift Container Platform 4.12Red Hat: Red Hat OpenShift Container Platform 4.13Red Hat: Red Hat OpenShift Container Platform 4.14Red Hat: Red Hat OpenShift Container Platform 4.15Red Hat: Red Hat OpenShift Container Platform 4.16Red Hat: Red Hat OpenShift Container Platform 4.17Red Hat: Red Hat OpenShift Container Platform 4.18Red Hat: Red Hat OpenShift Container Platform 4.19Red Hat: Red Hat OpenShift Container Platform 4.20Red Hat: Red Hat OpenShift Container Platform 4.21Siemens: SIMATIC S7-1500 CPU 1518-4 PN/DP MFPSiemens: SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPSiemens: SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c (opens in new tab)
- git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987 (opens in new tab)
- git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111 (opens in new tab)
- git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a (opens in new tab)
- git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e (opens in new tab)
- git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0 (opens in new tab)
- git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5 (opens in new tab)
- git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)