CVE-2026-23456

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-04-03. the CNA's CVSS baseline 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this week
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.2Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case

In decode_int(), the CONS case calls get_bits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The existing boundary check only validates the 2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint() reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte slab-out-of-bounds read.

Add a boundary check for len bytes after get_bits() and before get_uint().

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
42(Track)
EG Risk 42/100SSVC: 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
Severity82% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
43%
KEV
Not listed

Published

April 3, 2026

Last Modified

September 8, 2026

Advisory Details (8)

Auto-updated May 3, 2026
No patch confirmed yet.
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fb6c3596823ec5dd09c2123340330d7448f51a59
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c95dc674ebf01ecfb40388b6facfc89b81fed3b7
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a2cd54b9348e485d338b3c132338a4410c99afaf
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/774a434f8c9c8602a976b2536f65d0172a07f4d2
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6bce72daeccca9aa1746e92d6c3d4784e71f2ebb
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/52235bf88159a1ef16434ab49e47e99c8a09ab20
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/41b417ff73a24b2c68134992cc44c88db27f482d
generic

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1e3a3593162c96e8a8de48b1e14f60c3b57fca8a

Vendor Advisories for CVE-2026-23456(1)

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

Patch Availability(27)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-09-08ubuntu
ubuntulinux-virtual-6.8 (6.8.0-136.136) @ noble2026-09-08ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-09-08ubuntu
ubuntulinux-xilinx-zynqmp-tools-5.15.0-1075 (5.15.0-1075.79) @ jammy2026-09-08ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.66~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-09-08ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-09-08ubuntu
ubuntulinux-tools-nvidia-lowlatency-5.15 (5.15.0.1107.107) @ jammy2026-09-08ubuntu
ubuntulinux-tools-nvidia-tegra-rt-5.15 (5.15.0.1064.64) @ jammy2026-09-08ubuntu
ubuntulinux-tools-ibm-edge (5.15.0.1106.110~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-09-08ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-tools-oracle-lts-22.04 (5.15.0.1109.105) @ jammy2026-09-08ubuntu
ubuntulinux-tools-azure-fde-lts-22.04 (5.15.0.1117.126) @ jammy2026-09-08ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-09-08ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1033.34) @ noble2026-09-08ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-09-08ubuntu
ubuntulinux-tools-oracle-edge (5.15.0.1109.115~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-azure-fips-5.15 (5.15.0.1117.102) @ jammy2026-09-08ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1107.113~20.04.1) @ focal2026-09-08ubuntu
ubuntulinux-tools-intel-iotg-5.15 (5.15.0.1107.106) @ jammy2026-09-08ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1112.122~20.04.1) @ focal2026-09-08ubuntu
linuxKernel @ 5.10.253—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 (122 versions)6.19.10-1—

Weakness Classification(1)

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

All Vendor Advisories

(25)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× in last 7d / 32× 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 230 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-23456?
CVE-2026-23456 is a high vulnerability published on April 3, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: nfconntrackh323: fix OOB read in decode_int() CONS case In decodeint(), the CONS case calls getbits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The…
When was CVE-2026-23456 disclosed?
CVE-2026-23456 was first published in the National Vulnerability Database on April 3, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-23456 actively exploited?
CVE-2026-23456 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.2% of all scored CVEs.
What is the CVSS score of CVE-2026-23456?
CVE-2026-23456 has a CVSS v4.0 base score of 8.2 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-23456?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-23456, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-23456

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