{"id":"CVE-2026-63912","title":"xfrm: esp: restore combined single-frag length gate","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: esp: restore combined single-frag length gate\n\nThe ESP out-of-place fast path appends the trailer in esp_output_head()\nbefore esp_output_tail() allocates the dest…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= c075c3ea031757f8ea2d34567565b61a868c08d5 < 566295735530ee513326049b0540f32ec050bf2e","Linux >= a583f2f3c8788bffd7fd7baeb76bd6d80543d7ea < 5d7ab86e2b6bc23054616bf6ac562013bf60af8c","Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < 36519e3d941fc99d3b52c134dbaf311f987a4708","Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < 322e48187e0245ab2fff6fec2220b0cae677dbec","Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < b84091ceddc9f133229dceab3ccc930bf27f9cba","Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < c093468aea8277f77272a4f199b2e15e19cabb59","Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < 65f3b3fc2347b89fe21db1e92c7681368415f095","Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40","Linux 2c66b0c95bb0aa7652ba1eba293d0d5993b35a38","Linux ef6f83df1209a7d9bd1c605a62457d4c00f9179e","Linux 3defefd22ad5fbbe639b6157fb7e6311b2bf333d","Linux b657030870bb5351c5b1e84d4e9f186da6ca0496","Linux >= 5.10.113 < 5.10.259","Linux >= 5.15.36 < 5.15.210","Linux >= 4.14.288 < 4.15","Linux >= 4.19.252 < 4.20","Linux >= 5.4.205 < 5.5","Linux >= 5.17.5 < 5.18","Linux 5.18"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:33:08.898705Z"},"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:10.792Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63912","references":[{"url":"https://git.kernel.org/stable/c/566295735530ee513326049b0540f32ec050bf2e"},{"url":"https://git.kernel.org/stable/c/5d7ab86e2b6bc23054616bf6ac562013bf60af8c"},{"url":"https://git.kernel.org/stable/c/36519e3d941fc99d3b52c134dbaf311f987a4708"},{"url":"https://git.kernel.org/stable/c/322e48187e0245ab2fff6fec2220b0cae677dbec"},{"url":"https://git.kernel.org/stable/c/b84091ceddc9f133229dceab3ccc930bf27f9cba"},{"url":"https://git.kernel.org/stable/c/c093468aea8277f77272a4f199b2e15e19cabb59"},{"url":"https://git.kernel.org/stable/c/65f3b3fc2347b89fe21db1e92c7681368415f095"},{"url":"https://git.kernel.org/stable/c/dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40"}],"tags":["cve.org"],"epss":0.00714,"epssPercentile":0.52754,"ingestedAt":"2026-10-16T17:24:46.777Z","slug":"CVE-2026-63912","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: esp: restore combined single-frag length gate\n\nThe ESP out-of-place fast path appends the trailer in esp_output_head()\nbefore esp_output_tail() allocates the destination page frag. The\nhead-side gate currently checks skb->data_len and tailen separately, but\nthe tail code allocates a single destination frag from the combined\npost-trailer skb->data_len.\n\nReject the page-frag fast path when the combined aligned length exceeds a\npage. Otherwise skb_page_frag_refill() may fall back to a single page while\nthe destination sg still spans the combined skb->data_len.\n\nRestore this combined-length page gate for both IPv4 and IPv6.\n\n## Affected\n\n- `Linux >= c075c3ea031757f8ea2d34567565b61a868c08d5 < 566295735530ee513326049b0540f32ec050bf2e`\n- `Linux >= a583f2f3c8788bffd7fd7baeb76bd6d80543d7ea < 5d7ab86e2b6bc23054616bf6ac562013bf60af8c`\n- `Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < 36519e3d941fc99d3b52c134dbaf311f987a4708`\n- `Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < 322e48187e0245ab2fff6fec2220b0cae677dbec`\n- `Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < b84091ceddc9f133229dceab3ccc930bf27f9cba`\n- `Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < c093468aea8277f77272a4f199b2e15e19cabb59`\n- `Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < 65f3b3fc2347b89fe21db1e92c7681368415f095`\n- `Linux >= 5bd8baab087dff657e05387aee802e70304cc813 < dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40`\n- `Linux 2c66b0c95bb0aa7652ba1eba293d0d5993b35a38`\n- `Linux ef6f83df1209a7d9bd1c605a62457d4c00f9179e`\n- `Linux 3defefd22ad5fbbe639b6157fb7e6311b2bf333d`\n- `Linux b657030870bb5351c5b1e84d4e9f186da6ca0496`\n- `Linux >= 5.10.113 < 5.10.259`\n- `Linux >= 5.15.36 < 5.15.210`\n- `Linux >= 4.14.288 < 4.15`\n- `Linux >= 4.19.252 < 4.20`\n- `Linux >= 5.4.205 < 5.5`\n- `Linux >= 5.17.5 < 5.18`\n- `Linux 5.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}