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NVD / CVE Program· CNA Linux

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

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.11% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 06ce6fc106b16dec9b535950db626261be865e5b, 2a58899d11009bffc7b4b32a571858f381121837, 4485d79617520d84ba5a14515e2b5136007d6deb; azl3 kernel 6.6.141.1-1 on Azure Linux 3.0 6.6.143.1-1.

Low priority for now. Upgrade to Linux Linux 06ce6fc106b16dec9b535950db626261be865e5b, 2a58899d11009bffc7b4b32a571858f381121837, 4485d79617520d84ba5a14515e2b5136007d6deb; azl3 kernel 6.6.141.1-1 on Azure Linux 3.0 6.6.143.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jun 25, 2026
Updated
Oct 15, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.6 and later · before 5.10.259
  • linux linux kernel5.11 and later · before 5.15.210
  • linux linux kernel5.16 and later · before 6.1.176
  • linux linux kernel6.2 and later · before 6.6.143
  • linux linux kernel6.7 and later · before 6.12.94
  • linux linux kernel6.13 and later · before 6.18.36
  • linux linux kernel6.19 and later · before 7.0.13
  • linux linux kernel7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.6affected
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before f24a58c72a45f4c109f3557a760cc4b60b7a6037affected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before da8cbb64b47e9066b40af0de170901caf17b768caffected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before 4485d79617520d84ba5a14515e2b5136007d6debaffected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before 06ce6fc106b16dec9b535950db626261be865e5baffected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before dcb1bec1c32ee5c3878354e087cf5dbee2b7c7afaffected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before c32f30ef5e66adbfa102348e2e8a23776eb007cbaffected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before da8808463882c3f3c357b072e25053c2121f1419affected · git
    • 5609c185f24dffca5f6a9c127106869da150be03 and later · before 2a58899d11009bffc7b4b32a571858f381121837affected · git
    • before 4.6not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.13-17.0.13-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-53260Jun 25, 2026 · tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
    39Monitor
  • ← EarlierCVE-2026-53262Jun 25, 2026 · l2tp: pppol2tp: hold reference to session in pppol2tp_ioctl()
    31Monitor
  • Later →CVE-2026-53264Jun 25, 2026 · net/sched: act_api: use RCU with deferred freeing for action lifecycle
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux06ce6fc106b16dec9b535950db626261be865e5bVendor (CNA)
Linux Linux2a58899d11009bffc7b4b32a571858f381121837Vendor (CNA)
Linux Linux4485d79617520d84ba5a14515e2b5136007d6debVendor (CNA)
Linux Linuxc32f30ef5e66adbfa102348e2e8a23776eb007cbVendor (CNA)
Linux Linuxda8808463882c3f3c357b072e25053c2121f1419Vendor (CNA)
Linux Linuxda8cbb64b47e9066b40af0de170901caf17b768cVendor (CNA)
Linux Linuxdcb1bec1c32ee5c3878354e087cf5dbee2b7c7afVendor (CNA)
Linux Linuxf24a58c72a45f4c109f3557a760cc4b60b7a6037Vendor (CNA)
azl3 kernel 6.6.141.1-1 on Azure Linux 3.06.6.143.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-530881 days apartnet: bcmgenet: fix off-by-one in bcmgenet_put_txcb
    39Monitor
  • CVE-2026-533091 days apartocfs2/dlm: fix off-by-one in dlm_match_regions() region comparison
    39Monitor
  • CVE-2026-6404724 days apartnet: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring
    39Monitor
  • CVE-2026-530361 days apartbpf, arm64: Fix off-by-one in check_imm signed range check
    31Monitor
  • CVE-2026-5290716 days apartmedia: rockchip: rkcif: fix off by one bugs
    31Monitor
  • CVE-2024-57990484 days apartwifi: mt76: mt7925: fix off by one in mt7925_load_clc()
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-193 · Off-by-one Error

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records