CVE-2026-23304
ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()
Description
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.
INFO
Published Date :
March 25, 2026, 11:16 a.m.
Last Modified :
May 28, 2026, 2:34 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Linux kernel to the latest version.
- Recompile and install the kernel if necessary.
- Reboot the system after applying updates.
Public PoC/Exploit Available at Github
CVE-2026-23304 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
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CVE-2026-23304.
CWE - Common Weakness Enumeration
While CVE identifies
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weaknesses that can lead to vulnerabilities. CVE-2026-23304 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-23304
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
DSA and DLA for Debian last 14 days
Python
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The following list is the news that have been mention
CVE-2026-23304 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-23304 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
May. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.7 *cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.17 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.130 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.77 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.203 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.167 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.14 up to (excluding) 5.10.253 Added Reference Type kernel.org: https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 18, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 Added Reference https://git.kernel.org/stable/c/d542e2ac7f9e288d49735be0775611547ca4e0ee -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 25, 2026
Action Type Old Value New Value Added Description 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. Added Reference https://git.kernel.org/stable/c/0b5a7826020706057cc5a9d9009e667027f221ee Added Reference https://git.kernel.org/stable/c/2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a Added Reference https://git.kernel.org/stable/c/3310fc11fc47387d1dd4759b0bc961643ea11c7f Added Reference https://git.kernel.org/stable/c/4a48fe59f29f673a3d042d679f26629a9c3e29d4 Added Reference https://git.kernel.org/stable/c/581800298313c9fd75e94985e6d37d21b7e35d34 Added Reference https://git.kernel.org/stable/c/ae88c8256547b63980770a9ea7be73a15900d27e