Vulnerability Database

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Total vulnerabilities in the database

CVE-2026-53263 — linux / linux_kernel

Off-by-one Error

In the Linux kernel, the following vulnerability has been resolved:

6lowpan: fix off-by-one in multicast context address compression

The second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses &data[1] as destination and &ipaddr->s6_addr[11] as source, but both should be offset by one: &data[2] and &ipaddr->s6_addr[12] respectively.

This off-by-one has two consequences:

  1. data[1] is overwritten with s6_addr[11], corrupting the RIID field in the compressed multicast address
  2. data[5] is never written, so uninitialized kernel stack memory is transmitted over the network via lowpan_push_hc_data(), leaking kernel stack contents

The correct inline data layout must match what the decompression function lowpan_uncompress_multicast_ctx_daddr() expects: data[0..1] = s6_addr[1..2] (flags/scope + RIID) data[2..5] = s6_addr[12..15] (group ID)

Also zero-initialize the data array as a defensive measure against similar bugs in the future.

  • Published: Jun 25, 2026
  • Updated: Oct 17, 2026
  • CVE: CVE-2026-53263
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 5.5
  • AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWEs:

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