5.5

CVE-2026-23304: linux NULL Pointer Dereference

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2026-23304DEBIAN-CVE-2026-23304
Published 25-03-2026Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2026-23304 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.2% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.13%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 36 · Related 34
MGASA-2026-0097MGASA-2026-0098OPENSUSE-SU-2026:20572-1SUSE-SU-2026:21114-1SUSE-SU-2026:21123-1SUSE-SU-2026:21230-1

Timeline

  1. 25-03-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

0.00 pp

From 0.13% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.13%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu156 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < d542e2ac7f9e288d49735be0775611547ca4e0ee | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < 4a48fe59f29f673a3d042d679f26629a9c3e29d4 | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < 581800298313c9fd75e94985e6d37d21b7e35d34 | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < 3310fc11fc47387d1dd4759b0bc961643ea11c7f | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < 0b5a7826020706057cc5a9d9009e667027f221ee | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < ae88c8256547b63980770a9ea7be73a15900d27e | ≥ 4832c30d5458387ff2533ff66fbde26ad8bb5a2d, < 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a | 4.14
  • linux_kernel≥ 4.14, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.167 | ≥ 6.2, < 6.6.130 | ≥ 6.7, < 6.12.77 | ≥ 6.13, < 6.18.17 | ≥ 6.19, < 6.19.7 | 7.0:rc1 | 7.0:rc2
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.8-1

3 vendors · 159 products

References

44 links
Show all 44 references