5.5

CVE-2026-23381: linux NULL Pointer Dereference

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2026-23381DEBIAN-CVE-2026-23381
Published 25-03-2026Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2026-23381 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.6% 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
0.12%
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 37 · Related 34
MGASA-2026-0097MGASA-2026-0098OPENSUSE-SU-2026:20572-1RHSA-2026:25253SUSE-SU-2026:1573-1SUSE-SU-2026:21114-1

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: net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never initialized because inet6_init() exits before ndisc_init() is called which initializes it. Then, if neigh_suppress is enabled and an ICMPv6 Neighbor Discovery packet reaches the bridge, br_do_suppress_nd() will dereference ipv6_stub->nd_tbl which is NULL, passing it to neigh_lookup(). This causes a kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000268 Oops: 0000 [#1] PREEMPT SMP NOPTI [...] RIP: 0010:neigh_lookup+0x16/0xe0 [...] Call Trace: <IRQ> ? neigh_lookup+0x16/0xe0 br_do_suppress_nd+0x160/0x290 [bridge] br_handle_frame_finish+0x500/0x620 [bridge] br_handle_frame+0x353/0x440 [bridge] __netif_receive_skb_core.constprop.0+0x298/0x1110 __netif_receive_skb_one_core+0x3d/0xa0 process_backlog+0xa0/0x140 __napi_poll+0x2c/0x170 net_rx_action+0x2c4/0x3a0 handle_softirqs+0xd0/0x270 do_softirq+0x3f/0x60 Fix this by replacing IS_ENABLED(IPV6) call with ipv6_mod_enabled() in the callers. This is in essence disabling NS/NA suppression when IPv6 is disabled.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

0.00 pp

From 0.12% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.12%

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≥ ed842faeb2bd49256f00485402f3113205f91d30, < a9d712ccfeef737c0e700a4b5b98f310e07b6b60 | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < a5c56e65b685360dd3f2278aeff8c21061feb665 | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < 7a894eb5de246d79f13105c55a67381039a24d44 | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < a12cdaa3375f0bd3c8f4e564be7c143529abfe5b | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < aa73deb3b6b730ec280d45b3f423bfa9e17bc122 | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < 33dec6f10777d5a8f71c0a200f690da5ae3c2e55 | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < 20ef5c25422f97dd09d751e5ae6c18406cdc78e6 | ≥ ed842faeb2bd49256f00485402f3113205f91d30, < e5e890630533bdc15b26a34bb8e7ef539bdf1322 | 4.15
  • linux_kernel≥ 4.15.1, < 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 | 4.15 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
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