{"id":"CVE-2026-53263","title":"In the Linux kernel, the following vulnerability has been resolved:\n\n6lowpan: fix off-by-one in multicast context address compression\n\nThe second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses\n&data[1] as destination and &ipaddr->s…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\n6lowpan: fix off-by-one in multicast context address compression\n\nThe second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses\n&data[1] as destination and &ipaddr->s…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-193"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.6, < 5.10.259","linux_kernel >= 5.11, < 5.15.210","linux_kernel >= 5.16, < 6.1.176","linux_kernel >= 6.2, < 6.6.143","linux_kernel >= 6.7, < 6.12.94","linux_kernel >= 6.13, < 6.18.36","linux_kernel >= 6.19, < 7.0.13","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.13"],"published":"2026-06-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:20:07.663","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53263","references":[{"url":"https://git.kernel.org/stable/c/06ce6fc106b16dec9b535950db626261be865e5b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2a58899d11009bffc7b4b32a571858f381121837","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4485d79617520d84ba5a14515e2b5136007d6deb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c32f30ef5e66adbfa102348e2e8a23776eb007cb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/da8808463882c3f3c357b072e25053c2121f1419","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/da8cbb64b47e9066b40af0de170901caf17b768c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f24a58c72a45f4c109f3557a760cc4b60b7a6037","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00115,"epssPercentile":0.01418,"ingestedAt":"2026-10-15T03:30:12.911Z","slug":"CVE-2026-53263","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\n6lowpan: fix off-by-one in multicast context address compression\n\nThe second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses\n&data[1] as destination and &ipaddr->s6_addr[11] as source, but\nboth should be offset by one: &data[2] and &ipaddr->s6_addr[12]\nrespectively.\n\nThis off-by-one has two consequences:\n1. data[1] is overwritten with s6_addr[11], corrupting the RIID\n   field in the compressed multicast address\n2. data[5] is never written, so uninitialized kernel stack memory\n   is transmitted over the network via lowpan_push_hc_data(),\n   leaking kernel stack contents\n\nThe correct inline data layout must match what the decompression\nfunction lowpan_uncompress_multicast_ctx_daddr() expects:\n  data[0..1] = s6_addr[1..2]  (flags/scope + RIID)\n  data[2..5] = s6_addr[12..15] (group ID)\n\nAlso zero-initialize the data array as a defensive measure against\nsimilar bugs in the future.\n\n## Affected\n\n- `linux_kernel >= 4.6, < 5.10.259`\n- `linux_kernel >= 5.11, < 5.15.210`\n- `linux_kernel >= 5.16, < 6.1.176`\n- `linux_kernel >= 6.2, < 6.6.143`\n- `linux_kernel >= 6.7, < 6.12.94`\n- `linux_kernel >= 6.13, < 6.18.36`\n- `linux_kernel >= 6.19, < 7.0.13`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.13`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}