VulnerabilityPublished 25 Jun 2026Updated 6 Nov 2026

CVE-2026-53263: Linux kernel · 6lowpan: fix off-by-one in multicast context address compression

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in f24a58c72a45f4c109f3557a760cc4b60b7a6037 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:49 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in f24a58c72a45f4c109f3557a760cc4b60b7a6037, dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af, da8808463882c3f3c357b072e25053c2121f1419 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 5609c185f24dffca5f6a9c127106869da150be03, < f24a58c72a45f4c109f3557a760cc4b60b7a6037	Fixed in f24a58c72a45f4c109f3557a760cc4b60b7a6037
LinuxLinux	Affected ≥ 5609c185f24dffca5f6a9c127106869da150be03, < dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af	Fixed in dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af
LinuxLinux	Affected ≥ 5609c185f24dffca5f6a9c127106869da150be03, < da8808463882c3f3c357b072e25053c2121f1419	Fixed in da8808463882c3f3c357b072e25053c2121f1419
LinuxLinux	Affected ≥ 5609c185f24dffca5f6a9c127106869da150be03, < da8cbb64b47e9066b40af0de170901caf17b768c	Fixed in da8cbb64b47e9066b40af0de170901caf17b768c
LinuxLinux	Affected ≥ 5609c185f24dffca5f6a9c127106869da150be03, < c32f30ef5e66adbfa102348e2e8a23776eb007cb	Fixed in c32f30ef5e66adbfa102348e2e8a23776eb007cb
LinuxLinux	Affected ≥ 5609c185f24dffca5f6a9c127106869da150be03, < 4485d79617520d84ba5a14515e2b5136007d6deb	Fixed in 4485d79617520d84ba5a14515e2b5136007d6deb

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.

References

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