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NVD / CVE Program· CNA Linux

CVE-2026-72322: ipv6: mcast: Fix potential UAF in MLD delayed work

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.72% (FIRST EPSS); higher than 54.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 0401d6cf7877c9be36652385dfcbf7f891b8b590, 0458ba1cda830ba4ccfcd9e19c0891438bcdbe4e, 9815e834f5ff8b39e0ea9f0dbd532f4a3b8f0785.

Low priority for now. Upgrade to Linux Linux 0401d6cf7877c9be36652385dfcbf7f891b8b590, 0458ba1cda830ba4ccfcd9e19c0891438bcdbe4e, 9815e834f5ff8b39e0ea9f0dbd532f4a3b8f0785 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: ipv6: mcast: Fix potential UAF in MLD delayed work A race condition exists between device teardown and incoming MLD query processing, leading to a Use-After-Free in the MLD delayed work. During device destruction, the primary reference to inet6_dev is dropped, which can drop its refcount to 0. The actual freeing of inet6_dev memory is deferred via RCU. Concurrently, the packet receive path runs under RCU read lock and obtains the inet6_dev pointer. Because the memory is RCU-protected, CPU-0 can safely dereference inet6_dev even if its refcount has hit 0. However, if CPU-0 calls igmp6_event_query() and schedules delayed work, it attempts to acquire a reference using in6_dev_hold(). This increments the refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning. Since the inet6_dev memory is still scheduled to be freed after the RCU grace period, the device is freed while the work is still scheduled. When the work runs, it accesses the freed memory, causing a kernel panic. Fix this by using refcount_inc_not_zero() (via a new helper in6_dev_hold_safe()) to prevent acquiring a reference if the device is already being destroyed. If the refcount is 0, we do not schedule the work.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.7% · 54th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-72322

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • 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.

—

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

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before f12b63ef26a035c5a29b3ef56401e38199010d4aaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0401d6cf7877c9be36652385dfcbf7f891b8b590affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before f03b0a45535d49bdab7e502efaacee205b2a7865affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 9815e834f5ff8b39e0ea9f0dbd532f4a3b8f0785affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before ebbebf6cee950d7f1c81990256c0eae9e62572aeaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 9ce741c22df4fd9546e30306317ac7df3607e48faffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 0458ba1cda830ba4ccfcd9e19c0891438bcdbe4eaffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 9b26518b6896a16b809b1e42986f4ebac7bccc1eaffected · git
    • before 2.6.12not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-defaultbefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-docsbefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-ec2before 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-sourcebefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-symsbefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-tracebefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-xenbefore 3.0.101-108.223.13.0.101-108.223.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-72320Aug 15, 2026 · netfilter: nft_lookup: fix catchall element handling with inverted lookups
    36Monitor
  • ← EarlierCVE-2026-72321Aug 15, 2026 · ipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer()
    0Monitor
  • Later →CVE-2026-72323Aug 15, 2026 · ipv4: igmp: Fix potential UAF in igmp_gq_start_timer()
    39Monitor

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 Linux0401d6cf7877c9be36652385dfcbf7f891b8b590Vendor (CNA)
Linux Linux0458ba1cda830ba4ccfcd9e19c0891438bcdbe4eVendor (CNA)
Linux Linux9815e834f5ff8b39e0ea9f0dbd532f4a3b8f0785Vendor (CNA)
Linux Linux9b26518b6896a16b809b1e42986f4ebac7bccc1eVendor (CNA)
Linux Linux9ce741c22df4fd9546e30306317ac7df3607e48fVendor (CNA)
Linux Linuxebbebf6cee950d7f1c81990256c0eae9e62572aeVendor (CNA)
Linux Linuxf03b0a45535d49bdab7e502efaacee205b2a7865Vendor (CNA)
Linux Linuxf12b63ef26a035c5a29b3ef56401e38199010d4aVendor (CNA)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
suse:kernel-default3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-docs3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-ec23.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-source3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-syms3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-trace3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-xen3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage 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+1% in 7 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.

No nightly-computed relations.

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

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

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. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records