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NVD / CVE Program· CNA Linux

CVE-2026-68323: tipc: serialize udp bearer replicast list updates

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.10% (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 350e592ff4e30e48ffb55e142d11a73e63f4869c, 3ff143a884a19bfcf3aebd999b02274fe44f46f3, 3ff6b534d20824cddab99c81ea3bd1144e635626; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 350e592ff4e30e48ffb55e142d11a73e63f4869c, 3ff143a884a19bfcf3aebd999b02274fe44f46f3, 3ff6b534d20824cddab99c81ea3bd1144e635626; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: tipc: serialize udp bearer replicast list updates tipc_udp_rcast_add() and cleanup_bearer() both update ub->rcast.list with list_add_rcu() / list_del_rcu(), but nothing serializes them. The add runs from the encap receive softirq (via tipc_udp_rcast_disc()) without rtnl_lock(), so it can race the cleanup delete and corrupt the list: list_del corruption. prev->next should be ffff8880298d7ab8, but was ffff88802449ad38. (prev=ffff888027e3ec98) kernel BUG at lib/list_debug.c:62! RIP: __list_del_entry_valid_or_report+0x17a/0x200 Workqueue: events cleanup_bearer Call Trace: cleanup_bearer (net/tipc/udp_media.c:811) process_one_work (kernel/workqueue.c:3302) worker_thread (kernel/workqueue.c:3466) The bearer can be enabled from an unprivileged user namespace, as the TIPCv2 generic-netlink ops carry no GENL_ADMIN_PERM. Add a spinlock to struct udp_bearer and take it around the list_add_rcu() in tipc_udp_rcast_add() and the list_del_rcu() loop in cleanup_bearer() so the two writers can no longer corrupt the list. Reject a duplicate peer under the same lock before allocating, and remove tipc_udp_is_known_peer(). The old lockless pre-check in tipc_udp_rcast_disc() was racy: two softirqs discovering the same peer could both find it absent and add it twice. cleanup_bearer() runs from a workqueue after tipc_udp_disable() clears the bearer's up bit, so an encap softirq can still reach tipc_udp_rcast_add() and add a peer after cleanup_bearer() has already emptied the list, leaking that entry when the bearer is freed. Mark the bearer disabled under rcast_lock once the list is emptied and refuse further additions.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Aug 10, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 0th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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.

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When you'll hear from us

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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.

—

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

    • 4.9affected
    • ef20cd4dd1633987bcf46ac34ace2c8af212361f and later · before c148aec60ef1e806cbc9da44b3d89409df998adeaffected · git
    • ef20cd4dd1633987bcf46ac34ace2c8af212361f and later · before 3ff6b534d20824cddab99c81ea3bd1144e635626affected · git
    • ef20cd4dd1633987bcf46ac34ace2c8af212361f and later · before 3ff143a884a19bfcf3aebd999b02274fe44f46f3affected · git
    • ef20cd4dd1633987bcf46ac34ace2c8af212361f and later · before 5d3cea7d41dc72073fea6f879815c9b57c3b330daffected · git
    • ef20cd4dd1633987bcf46ac34ace2c8af212361f and later · before d70c81001df9320d3445e664428a1d408b5ba896affected · git
    • ef20cd4dd1633987bcf46ac34ace2c8af212361f and later · before 350e592ff4e30e48ffb55e142d11a73e63f4869caffected · git
    • before 4.9not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:14linuxbefore 7.1.6-17.1.6-1
SUSE:Linux Enterprise Live Patching 12 SP5kernel-defaultbefore 4.12.14-122.336.14.12.14-122.336.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_89before 1-8.3.11-8.3.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-sourcebefore 4.12.14-122.336.14.12.14-122.336.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-symsbefore 4.12.14-122.336.14.12.14-122.336.1
SUSE:Linux Micro 6.0kernel-defaultbefore 6.4.0-159998.54.16.4.0-159998.54.1
SUSE:Linux Micro 6.0kernel-default-basebefore 6.4.0-159998.54.1.159998.21.406.4.0-159998.54.1.159998.21.40
SUSE:Linux Micro 6.0kernel-kvmsmallbefore 6.4.0-159998.54.16.4.0-159998.54.1
SUSE:Linux Micro 6.0kernel-sourcebefore 6.4.0-159998.54.16.4.0-159998.54.1
SUSE:Linux Micro 6.1kernel-default-basebefore 6.4.0-159998.54.1.159998.21.396.4.0-159998.54.1.159998.21.39

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-2026-68318Aug 10, 2026 · pds_core: fix use-after-free on workqueue during remove
    0Monitor
  • ← EarlierCVE-2026-68320Aug 10, 2026 · sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid
    29Monitor
  • Later →CVE-2026-68326Aug 10, 2026 · wifi: mwifiex: bound uAP association event IEs to the event buffer
    35Monitor

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 Linux350e592ff4e30e48ffb55e142d11a73e63f4869cVendor (CNA)
Linux Linux3ff143a884a19bfcf3aebd999b02274fe44f46f3Vendor (CNA)
Linux Linux3ff6b534d20824cddab99c81ea3bd1144e635626Vendor (CNA)
Linux Linux5d3cea7d41dc72073fea6f879815c9b57c3b330dVendor (CNA)
Linux Linuxc148aec60ef1e806cbc9da44b3d89409df998adeVendor (CNA)
Linux Linuxd70c81001df9320d3445e664428a1d408b5ba896Vendor (CNA)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux7.1.6-1 · Debian:14Package registry (OSV)
suse:kernel-default4.12.14-122.336.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package registry (OSV)
suse:kernel-default6.4.0-159998.54.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-default-base6.4.0-159998.54.1.159998.21.40 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-kvmsmall6.4.0-159998.54.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-source4.12.14-122.336.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kernel-source6.4.0-159998.54.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-syms4.12.14-122.336.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kgraft-patch-SLE12-SP5_Update_891-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package 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-2026-720645 days apartnet: mana: Sync page pool RX frags for CPU
    39Monitor
  • CVE-2026-6397822 days apartnet/handshake: Drain pending requests at net namespace exit
    39Monitor
  • CVE-2026-683290 days apartiommu/amd: Wait for completion instead of returning early in iommu_completion_wait()
    35Monitor
  • CVE-2026-645616 days apartKVM: x86: Check for invalid/obsolete root *after* making MMU pages available
    35Monitor
  • CVE-2026-682450 days apartdrm/amdgpu: fix lifetime issue of amdgpu_vm_get_task_info_pasid()
    31Monitor
  • CVE-2026-683380 days apartnet/packet: avoid fanout hook re-registration after unregister
    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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/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.

ATT&CK techniques

—

Change log

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

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

References

Show all references (5 more)

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

All records