# CVE-2026-46300 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. - Page: https://www.vulneraibility.com/cve/CVE-2026-46300 - CVSS: 7.8 - Known exploited: yes, in CISA KEV since 2026-10-28; CISA due date 2026-10-31 - EPSS: 16.13% (percentile 97.0) - Public exploit code: 1 on Exploit-DB · 1 Metasploit module · 16 GitHub proofs of concept (first 2026-05-14) - CISA SSVC: exploitation active, automatable no, technical impact total (assessed 2026-05-14) - Weakness: CWE-123, CWE-456 - Published: 2026-05-23 ## Affected versions - Linux: affected >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 3599e6b3cc1ada96883d496a50a210d3afbb6987; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 78bf6b6bb19541d19fbda6242e7cfe2c682763c0; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 3bd9e113d50034db99d7ef69fd8e5242d15e414a; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < 3884358a9286b17f389a72b1426fc4547c23c111; >= cef401de7be8c4e155c6746bfccf721a4fa5fab9 and < f84eca5817390257cef78013d0112481c503b4a3; 3.9; fixed in < 3.9, >= 5.10.257 and <= 5.10.*, >= 5.15.208 and <= 5.15.*, >= 6.1.174 and <= 6.1.*, >= 6.6.141 and <= 6.6.*, >= 6.12.91 and <= 6.12.*, >= 6.18.33 and <= 6.18.*, >= 7.0.10 and <= 7.0.*, >= 7.1 and <= * A version outside these ranges is not a statement that it is unaffected. ## References - [other] https://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987 - [other] https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c - [other] https://git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5 - [other] https://git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0 - [other] https://git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e - [other] https://git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a - [other] https://git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111 - [other] https://git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3 - [other] http://www.openwall.com/lists/oss-security/2026/05/13/5 - [other] http://www.openwall.com/lists/oss-security/2026/05/21/11 - [other] http://www.openwall.com/lists/oss-security/2026/05/21/12 - [other] http://www.openwall.com/lists/oss-security/2026/05/21/13 - [other] https://access.redhat.com/security/cve/CVE-2026-46300 - [other] https://bugzilla.redhat.com/show_bug.cgi?id=2477015 - [other] https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46300.json - [advisory] https://access.redhat.com/errata/RHSA-2026:19540 - [advisory] https://access.redhat.com/errata/RHSA-2026:33486 - [advisory] https://access.redhat.com/errata/RHBA-2026:20032 - [advisory] https://access.redhat.com/errata/RHSA-2026:21695 - [advisory] https://access.redhat.com/errata/RHSA-2026:21690 - [advisory] https://access.redhat.com/errata/RHSA-2026:28887 - [advisory] https://access.redhat.com/errata/RHSA-2026:23233 - [advisory] https://access.redhat.com/errata/RHSA-2026:20087 - [advisory] https://access.redhat.com/errata/RHSA-2026:25044 - [advisory] https://access.redhat.com/errata/RHSA-2026:34098 - [advisory] https://access.redhat.com/errata/RHSA-2026:21656 - [advisory] https://access.redhat.com/errata/RHSA-2026:23245 - [advisory] https://access.redhat.com/errata/RHSA-2026:21702 - [advisory] https://access.redhat.com/errata/RHSA-2026:23240 - [advisory] https://access.redhat.com/errata/RHSA-2026:20299 - [advisory] https://access.redhat.com/errata/RHSA-2026:19569 - [advisory] https://access.redhat.com/errata/RHSA-2026:19705 - [advisory] https://access.redhat.com/errata/RHSA-2026:20593 - [advisory] https://access.redhat.com/errata/RHSA-2026:20054 - [advisory] https://access.redhat.com/errata/RHSA-2026:20129 - [advisory] https://access.redhat.com/errata/RHSA-2026:19568 - [advisory] https://access.redhat.com/errata/RHSA-2026:19666 - [advisory] https://access.redhat.com/errata/RHSA-2026:23470 - [advisory] https://access.redhat.com/errata/RHSA-2026:20130 - [advisory] https://access.redhat.com/errata/RHSA-2026:20051 - [advisory] https://access.redhat.com/errata/RHSA-2026:19521 - [advisory] https://access.redhat.com/errata/RHSA-2026:23471 - [advisory] https://access.redhat.com/errata/RHSA-2026:23469 - [advisory] https://access.redhat.com/errata/RHSA-2026:24814 - [advisory] https://access.redhat.com/errata/RHSA-2026:23468 - [advisory] https://access.redhat.com/errata/RHSA-2026:19664 - [advisory] https://access.redhat.com/errata/RHSA-2026:19711 - [advisory] https://access.redhat.com/errata/RHSA-2026:19875 - [other] https://cert-portal.siemens.com/productcert/html/ssa-082556.html - [other] https://cert-portal.siemens.com/productcert/html/ssa-019113.html --- Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.