CVE-2026-53263

Kernel-stack disclosure via misoffset multicast compression

Published Jun 25, 2026 · Updated Jun 25, 2026

Off-by-one error in 6LoWPAN multicast compression in Linux Kernel allows local users to disclose kernel-stack data in emitted packets. The second memcpy in lowpan_iphc_mcast_ctx_addr_compress() copies from source byte 11 into data[1], overwriting the RIID, while data[5] remains uninitialized and is sent by lowpan_push_hc_data(). Reachability requires local low-privilege access and a configured 6LoWPAN path that invokes multicast context compression; each affected packet corrupts its RIID and exposes one kernel-stack byte.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Off-by-one error in 6LoWPAN multicast compression in Linux Kernel allows local users to disclose kernel-stack data in emitted packets. The second memcpy in lowpan_iphc_mcast_ctx_addr_compress() copies from source byte 11 into data[1], overwriting the RIID, while data[5] remains uninitialized and is sent by lowpan_push_hc_data(). Reachability requires local low-privilege access and a configured 6LoWPAN path that invokes multicast context compression; each affected packet corrupts its RIID and exposes one kernel-stack byte.

The record

CVE
CVE-2026-53263
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-193, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.6
  2. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <06ce6fc106b16dec9b535950db626261be865e5b
  3. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <2a58899d11009bffc7b4b32a571858f381121837
  4. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <4485d79617520d84ba5a14515e2b5136007d6deb
  5. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <c32f30ef5e66adbfa102348e2e8a23776eb007cb
  6. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <da8808463882c3f3c357b072e25053c2121f1419
  7. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <da8cbb64b47e9066b40af0de170901caf17b768c
  8. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af
  9. Affected versionversion=5609c185f24dffca5f6a9c127106869da150be03 <f24a58c72a45f4c109f3557a760cc4b60b7a6037

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.6; version=5609c185f24dffca5f6a9c127106869da150be03 <06ce6fc106b16dec9b535950db626261be865e5b; version=5609c185f24dffca5f6a9c127106869da150be03 <2a58899d11009bffc7b4b32a571858f381121837; version=5609c185f24dffca5f6a9c127106869da150be03 <4485d79617520d84ba5a14515e2b5136007d6deb; version=5609c185f24dffca5f6a9c127106869da150be03 <c32f30ef5e66adbfa102348e2e8a23776eb007cb; version=5609c185f24dffca5f6a9c127106869da150be03 <da8808463882c3f3c357b072e25053c2121f1419; version=5609c185f24dffca5f6a9c127106869da150be03 <da8cbb64b47e9066b40af0de170901caf17b768c; version=5609c185f24dffca5f6a9c127106869da150be03 <dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af; version=5609c185f24dffca5f6a9c127106869da150be03 <f24a58c72a45f4c109f3557a760cc4b60b7a6037

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-193Off-by-one Error
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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