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NVD / CVE Program· CNA Linux

CVE-2026-64545: net, bpf: check master for NULL in xdp_master_redirect()

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 0.57% (FIRST EPSS).
  • 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 03b743586a2469744e96e9c1015096d07240935d, 3876318ea54e83eb70982b8280a3c5e4e32269bf, 4edbcacca09f92b85d3951b6add11894b20a84bc.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 03b743586a2469744e96e9c1015096d07240935d, 3876318ea54e83eb70982b8280a3c5e4e32269bf, 4edbcacca09f92b85d3951b6add11894b20a84bc 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: net, bpf: check master for NULL in xdp_master_redirect() xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns NULL when the receiving device has no upper-master adjacency. The reach guard only checks netif_is_bond_slave(). On bond slave release bond_upper_dev_unlink() drops the upper-master adjacency before clearing IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window still passes netif_is_bond_slave() while master is already NULL, and faults on master->flags at offset 0xb0: BUG: kernel NULL pointer dereference, address: 00000000000000b0 RIP: 0010:xdp_master_redirect (net/core/filter.c:4432) Call Trace: xdp_master_redirect (net/core/filter.c:4432) bpf_prog_run_generic_xdp (include/net/xdp.h:700) do_xdp_generic (net/core/dev.c:5608) __netif_receive_skb_one_core (net/core/dev.c:6204) process_backlog (net/core/dev.c:6319) __napi_poll (net/core/dev.c:7729) net_rx_action (net/core/dev.c:7792) handle_softirqs (kernel/softirq.c:622) __dev_queue_xmit (include/linux/bottom_half.h:33) packet_sendmsg (net/packet/af_packet.c:3082) __sys_sendto (net/socket.c:2252) Kernel panic - not syncing: Fatal exception in interrupt The missing check dates back to the original code; commit 1921f91298d1 ("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master") later added the master->flags read where the fault now lands but kept the unconditional deref. Check master for NULL before use; a NULL master is treated the same as one that is not up.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jul 27, 2026
Updated
Oct 19, 2026
EPSS
0.5% · 47th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.5
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

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Follow CVE-2026-64545

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

    • 5.15affected
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before c99ca049e910d61ddbd28cc2c47242f2bfbb4970affected · git
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before e2a56441233131fe18a76001de347ecda217e40caffected · git
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before 3876318ea54e83eb70982b8280a3c5e4e32269bfaffected · git
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before 4edbcacca09f92b85d3951b6add11894b20a84bcaffected · git
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before 03b743586a2469744e96e9c1015096d07240935daffected · git
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before 89c103d702b25ceb2d097faf854deb47b53b17ffaffected · git
    • 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 and later · before e82d8cc4321c373dc46e741cd2dfdaa7921fddb7affected · git
    • before 5.15not affected · semver
    • 5.15.212 and later · up to and including 5.15.*not 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:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

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-2026-64543Jul 27, 2026 · tipc: fix use-after-free of the discoverer in tipc_disc_rcv()
    31Monitor
  • ← EarlierCVE-2026-64544Jul 27, 2026 · crypto: asymmetric_keys - fix OOB read in pefile_digest_pe_contents
    0Monitor
  • Later →CVE-2026-64546Jul 27, 2026 · drm/edid: fix OOB read in drm_parse_tiled_block()
    28Monitor

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 Linux03b743586a2469744e96e9c1015096d07240935dVendor (CNA)
Linux Linux3876318ea54e83eb70982b8280a3c5e4e32269bfVendor (CNA)
Linux Linux4edbcacca09f92b85d3951b6add11894b20a84bcVendor (CNA)
Linux Linux89c103d702b25ceb2d097faf854deb47b53b17ffVendor (CNA)
Linux Linuxc99ca049e910d61ddbd28cc2c47242f2bfbb4970Vendor (CNA)
Linux Linuxe2a56441233131fe18a76001de347ecda217e40cVendor (CNA)
Linux Linuxe82d8cc4321c373dc46e741cd2dfdaa7921fddb7Vendor (CNA)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · 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-2026-6813614 days apartnet: gro: fix double aggregation of flush-marked skbs
    39Monitor
  • CVE-2026-6838514 days aparts390/checksum: Fix csum_partial() without vector facility
    39Monitor
  • CVE-2026-6835414 days apartfirewire: net: Fix fragmented datagram reassembly
    35Monitor
  • CVE-2025-68818195 days apartscsi: Revert "scsi: qla2xxx: Perform lockless command completion in abort path"
    35Monitor
  • CVE-2026-7203519 days apartnet/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked
    32Monitor
  • CVE-2026-6830514 days apartdrm/xe/vf: Add drm_dev guards when detaching CCS read/write buffers
    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

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

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 (8 more)

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

All records