CVE-2026-23381

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-03-25. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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: ? 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 v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

March 25, 2026

Last Modified

July 14, 2026

Advisory Details (10)

Auto-updated Jul 17, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

SSA-082556

https://cert-portal.siemens.com/productcert/html/ssa-082556.html
generic

SSA-019113

https://cert-portal.siemens.com/productcert/html/ssa-019113.html
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e5e890630533bdc15b26a34bb8e7ef539bdf1322
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/aa73deb3b6b730ec280d45b3f423bfa9e17bc122
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a9d712ccfeef737c0e700a4b5b98f310e07b6b60
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a5c56e65b685360dd3f2278aeff8c21061feb665
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a12cdaa3375f0bd3c8f4e564be7c143529abfe5b
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7a894eb5de246d79f13105c55a67381039a24d44
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/33dec6f10777d5a8f71c0a200f690da5ae3c2e55
generic

net: bridge: fix nd_tbl NULL dereference when IPv6 is disabled - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/20ef5c25422f97dd09d751e5ae6c18406cdc78e6

Vendor Advisories for CVE-2026-23381(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.10.253—osv
linuxKernel @ 6.1.167—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (53 versions)5.10.257-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.164-1~deb11u1 (16 versions)6.1.170-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (48 versions)6.1.170-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (117 versions)6.19.8-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(24)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 6× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 194 total refreshes for this CVE.

  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-02 15:01 UTCOSV refresh
  3. 2026-09-02 14:11 UTCEPSS rescore
  4. 2026-09-01 13:53 UTCEPSS rescore
  5. 2026-09-01 04:39 UTCEPSS rescore
  6. 2026-08-30 19:17 UTCEPSS rescore
  7. 2026-08-28 21:41 UTCEPSS rescore
  8. 2026-08-27 14:25 UTCEPSS rescore
  9. 2026-08-26 14:46 UTCEPSS rescore
  10. 2026-08-25 13:48 UTCEPSS rescore
  11. 2026-08-21 23:49 UTCEPSS rescore
  12. 2026-08-20 22:55 UTCEPSS rescore
  13. 2026-08-19 17:03 UTCEPSS rescore
  14. 2026-08-18 13:48 UTCEPSS rescore
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-16 14:56 UTCEPSS rescore
  17. 2026-08-16 10:24 UTCEG score recompute
  18. 2026-08-16 10:24 UTCVendor advisory
  19. 2026-08-16 10:24 UTCGHSA enrichment
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-15 01:30 UTCEPSS rescore
  22. 2026-08-14 06:43 UTCEG score recompute
  23. 2026-08-14 06:43 UTCVendor advisory
  24. 2026-08-14 06:43 UTCGHSA enrichment
  25. 2026-08-13 22:00 UTCEPSS rescore
Show 75 more
  1. 2026-08-12 20:58 UTCEG score recompute
  2. 2026-08-12 20:58 UTCVendor advisory
  3. 2026-08-12 20:58 UTCGHSA enrichment
  4. 2026-08-12 13:50 UTCEPSS rescore
  5. 2026-08-11 13:42 UTCEPSS rescore
  6. 2026-08-11 04:13 UTCEG score recompute
  7. 2026-08-11 04:13 UTCVendor advisory
  8. 2026-08-11 04:12 UTCGHSA enrichment
  9. 2026-08-11 00:00 UTCEPSS rescore
  10. 2026-08-10 05:14 UTCEG score recompute
  11. 2026-08-10 05:14 UTCVendor advisory
  12. 2026-08-10 05:14 UTCGHSA enrichment
  13. 2026-08-09 13:46 UTCEPSS rescore
  14. 2026-08-09 06:15 UTCEG score recompute
  15. 2026-08-09 06:15 UTCVendor advisory
  16. 2026-08-09 06:15 UTCGHSA enrichment
  17. 2026-08-08 16:37 UTCEPSS rescore
  18. 2026-08-07 16:34 UTCEG score recompute
  19. 2026-08-07 16:34 UTCVendor advisory
  20. 2026-08-07 16:34 UTCGHSA enrichment
  21. 2026-08-06 13:46 UTCEPSS rescore
  22. 2026-08-06 01:04 UTCEG score recompute
  23. 2026-08-06 01:04 UTCVendor advisory
  24. 2026-08-06 01:04 UTCGHSA enrichment
  25. 2026-08-05 19:17 UTCEPSS rescore
  26. 2026-08-04 10:38 UTCEPSS rescore
  27. 2026-08-03 23:50 UTCEG score recompute
  28. 2026-08-03 23:50 UTCVendor advisory
  29. 2026-08-03 23:50 UTCGHSA enrichment
  30. 2026-08-03 10:35 UTCEPSS rescore
  31. 2026-08-02 15:37 UTCEG score recompute
  32. 2026-08-02 15:37 UTCVendor advisory
  33. 2026-08-02 15:37 UTCGHSA enrichment
  34. 2026-08-02 02:26 UTCEPSS rescore
  35. 2026-08-01 04:15 UTCEPSS rescore
  36. 2026-07-30 01:30 UTCEPSS rescore
  37. 2026-07-27 14:13 UTCEPSS rescore
  38. 2026-07-26 14:54 UTCEPSS rescore
  39. 2026-07-26 14:54 UTCEPSS rescore
  40. 2026-07-25 14:17 UTCEPSS rescore
  41. 2026-07-25 14:17 UTCEPSS rescore
  42. 2026-07-24 14:17 UTCEPSS rescore
  43. 2026-07-23 14:18 UTCEPSS rescore
  44. 2026-07-23 14:18 UTCEPSS rescore
  45. 2026-07-23 03:07 UTCEG score recompute
  46. 2026-07-22 14:08 UTCEPSS rescore
  47. 2026-07-21 15:24 UTCEPSS rescore
  48. 2026-07-21 15:24 UTCEPSS rescore
  49. 2026-07-20 17:08 UTCEPSS rescore
  50. 2026-07-19 14:31 UTCEPSS rescore
  51. 2026-07-19 14:31 UTCEPSS rescore
  52. 2026-07-18 10:04 UTCEPSS rescore
  53. 2026-07-18 10:04 UTCEPSS rescore
  54. 2026-07-17 07:16 UTCOSV refresh
  55. 2026-07-16 17:03 UTCEPSS rescore
  56. 2026-07-16 17:03 UTCEPSS rescore
  57. 2026-07-15 16:57 UTCEPSS rescore
  58. 2026-07-15 16:57 UTCEPSS rescore
  59. 2026-07-15 02:00 UTCEPSS rescore
  60. 2026-07-15 02:00 UTCEPSS rescore
  61. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  62. 2026-07-14 13:11 UTCMITRE cvelistV5
  63. 2026-07-13 22:30 UTCEPSS rescore
  64. 2026-07-13 06:13 UTCEPSS rescore
  65. 2026-07-13 06:13 UTCEPSS rescore
  66. 2026-07-12 05:46 UTCEPSS rescore
  67. 2026-07-12 05:46 UTCEPSS rescore
  68. 2026-07-11 08:27 UTCEPSS rescore
  69. 2026-07-09 19:10 UTCEPSS rescore
  70. 2026-07-08 15:15 UTCEPSS rescore
  71. 2026-07-08 15:15 UTCEPSS rescore
  72. 2026-07-06 16:27 UTCEPSS rescore
  73. 2026-07-06 16:27 UTCEPSS rescore
  74. 2026-07-06 02:23 UTCEPSS rescore
  75. 2026-07-06 02:23 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-23381?
CVE-2026-23381 is a medium vulnerability published on March 25, 2026. 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 inet6init() exits before ndiscinit() is called which initializes it. Then, if…
When was CVE-2026-23381 disclosed?
CVE-2026-23381 was first published in the National Vulnerability Database on March 25, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23381 actively exploited?
CVE-2026-23381 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.0% of all scored CVEs.
What is the CVSS score of CVE-2026-23381?
CVE-2026-23381 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-23381?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23381, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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