CVE-2026-53263

Description

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.

CVSS 3.1

5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

0.16% probability · 6th percentile

CISA KEV

Not listed

Weakness

CWE-193

Affected

linux/linux kernel

Source

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.