NVD / CVE Program· CNA Linux

CVE-2026-23304: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()

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: 0.13% (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 0b5a7826020706057cc5a9d9009e667027f221ee, 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a, 3310fc11fc47387d1dd4759b0bc961643ea11c7f; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1.

Low priority for now. Upgrade to Linux Linux 0b5a7826020706057cc5a9d9009e667027f221ee, 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a, 3310fc11fc47387d1dd4759b0bc961643ea11c7f; azl3 kernel 6.6.126.1-1 on Azure Linux 3.0 6.6.130.1-1 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: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too.

MediumCVSS 5.5 · v3.1—No exploit Fix available

BDU:2026-12318

Published: Mar 25, 2026
Updated: Nov 5, 2026
EPSS: 0.1% · 2th percentile
CWE: CWE-476

Report tools

JSON

Action score

Monitor

Low priority for now.

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

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

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.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

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

linux linux kernel4.14 and later · before 5.10.253
linux linux kernel5.11 and later · before 5.15.203
linux linux kernel5.16 and later · before 6.1.167
linux linux kernel6.2 and later · before 6.6.130
linux linux kernel6.7 and later · before 6.12.77
linux linux kernel6.13 and later · before 6.18.17
linux linux kernel6.19 and later · before 6.19.7
linux linux kernel7.0

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
- 4.14affected
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before d542e2ac7f9e288d49735be0775611547ca4e0eeaffected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before a73fe9f4ae84a239d5b2686f47a58c158aee2eb4affected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before 4a48fe59f29f673a3d042d679f26629a9c3e29d4affected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before 581800298313c9fd75e94985e6d37d21b7e35d34affected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before 3310fc11fc47387d1dd4759b0bc961643ea11c7faffected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before 0b5a7826020706057cc5a9d9009e667027f221eeaffected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before ae88c8256547b63980770a9ea7be73a15900d27eaffected · git
- 4832c30d5458387ff2533ff66fbde26ad8bb5a2d and later · before 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5aaffected · git
- before 4.14not affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.170-1	6.1.170-1
Debian:13	linux	before 6.12.85-1	6.12.85-1
Debian:14	linux	before 6.19.8-1	6.19.8-1

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-2026-23302Mar 25, 2026 · net: annotate data-races around sk->sk_{data_ready,write_space}
18Monitor
← EarlierCVE-2026-23303Mar 25, 2026 · smb: client: Don't log plaintext credentials in cifs_set_cifscreds
22Monitor
Later →CVE-2026-23307Mar 25, 2026 · can: ems_usb: ems_usb_read_bulk_callback(): check the proper length of a message
22Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
Linux Linux	0b5a7826020706057cc5a9d9009e667027f221ee	Vendor (CNA)
Linux Linux	2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a	Vendor (CNA)
Linux Linux	3310fc11fc47387d1dd4759b0bc961643ea11c7f	Vendor (CNA)
Linux Linux	4a48fe59f29f673a3d042d679f26629a9c3e29d4	Vendor (CNA)
Linux Linux	581800298313c9fd75e94985e6d37d21b7e35d34	Vendor (CNA)
Linux Linux	a73fe9f4ae84a239d5b2686f47a58c158aee2eb4	Vendor (CNA)
Linux Linux	ae88c8256547b63980770a9ea7be73a15900d27e	Vendor (CNA)
Linux Linux	d542e2ac7f9e288d49735be0775611547ca4e0ee	Vendor (CNA)
azl3 kernel 6.6.126.1-1 on Azure Linux 3.0	6.6.130.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.170-1 · Debian:12	Package 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.

No history yet (it accumulates with the daily EPSS job).

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

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-476 · NULL Pointer Dereference

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

SSVC exploitation— → noneNov 5, 2026, 11:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

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

References

git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee

Show all references (11 more)

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

All records