CVE-2025-40206

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.8 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:linux, epss
Trending — 6 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

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

netfilter: nft_objref: validate objref and objrefmap expressions

Referencing a synproxy stateful object from OUTPUT hook causes kernel crash due to infinite recursive calls:

BUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12) [...] Call Trace: __find_rr_leaf+0x99/0x230 fib6_table_lookup+0x13b/0x2d0 ip6_pol_route+0xa4/0x400 fib6_rule_lookup+0x156/0x240 ip6_route_output_flags+0xc6/0x150 __nf_ip6_route+0x23/0x50 synproxy_send_tcp_ipv6+0x106/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 nft_synproxy_do_eval+0x263/0x310 nft_do_chain+0x5a8/0x5f0 [nf_tables nft_do_chain_inet+0x98/0x110 nf_hook_slow+0x43/0xc0 __ip6_local_out+0xf0/0x170 ip6_local_out+0x17/0x70 synproxy_send_tcp_ipv6+0x1a2/0x200 synproxy_send_client_synack_ipv6+0x1aa/0x1f0 [...]

Implement objref and objrefmap expression validate functions.

Currently, only NFT_OBJECT_SYNPROXY object type requires validation. This will also handle a jump to a chain using a synproxy object from the OUTPUT hook.

Now when trying to reference a synproxy object in the OUTPUT hook, nft will produce the following error:

synproxy_crash.nft: Error: Could not process rule: Operation not supported synproxy name mysynproxy ^^^^^^^^^^^^^^^^^^^^^^^^

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

November 12, 2025

Last Modified

July 30, 2026

Advisory Details (4)

Auto-updated Jul 30, 2026
No patch confirmed yet.
generic

netfilter: nft_objref: validate objref and objrefmap expressions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f359b809d54c6e3dd1d039b97e0b68390b0e53e4
generic

netfilter: nft_objref: validate objref and objrefmap expressions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7ea55a44493a5a36c3b3293b88bbe4841f9dbaf0
generic

netfilter: nft_objref: validate objref and objrefmap expressions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4c1cf72ec10be5a9ad264650cadffa1fbce6fabd
generic

netfilter: nft_objref: validate objref and objrefmap expressions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0028e0134c64d9ed21728341a74fcfc59cd0f944

Vendor Advisories for CVE-2025-40206(2)

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

Patch Availability(16)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-azure-6.17 (6.17.0-1008.8) @ questing2026-07-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-106.106) @ noble2026-07-30ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1049.52.1) @ noble2026-07-30ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1052.55+fips1) @ noble2026-07-30ubuntu
ubuntulinux-tools-realtime-6.8.1 (6.8.1-1045.46) @ noble2026-07-30ubuntu
ubuntulinux-tools-aws-edge (6.8.0-1050.53~22.04.1) @ jammy2026-07-30ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1051.57) @ noble2026-07-30ubuntu
ubuntulinux-tools-azure-edge (6.8.0-1051.57~22.04.1) @ jammy2026-07-30ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2040.41) @ noble2026-07-30ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1052.58+fips1) @ noble2026-07-30ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1029.30) @ noble2026-07-30ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.17.0-14.14) @ questing2026-07-30ubuntu
ubuntulinux-tools-gcp-64k-6.17 (6.17.0-1007.7) @ questing2026-07-30ubuntu
ubuntulinux-tools-oracle-64k-6.17 (6.17.0-1007.7) @ questing2026-07-30ubuntu
ubuntulinux-tools-oem-6.17 (6.17.0-1011.11) @ noble2026-07-30ubuntu
linuxKernel @ 6.6.113—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.

Additional Vendor Advisories

(15)

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 10× in last 7d / 42× 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 131 total refreshes for this CVE.

  1. 2026-08-01 04:15 UTCEPSS rescore
  2. 2026-07-30 16:27 UTCEPSS rescore
  3. 2026-07-30 06:26 UTCEG score recompute▲ 7.80
  4. 2026-07-30 06:26 UTCVendor advisory
  5. 2026-07-30 06:25 UTCGHSA enrichment
  6. 2026-07-30 06:18 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  7. 2026-07-30 01:29 UTCEPSS rescore
  8. 2026-07-28 15:35 UTCEPSS rescore
  9. 2026-07-27 07:09 UTCOSV refresh
  10. 2026-07-26 14:54 UTCEPSS rescore
  11. 2026-07-24 14:17 UTCEPSS rescore
  12. 2026-07-23 02:55 UTCEG score recompute
  13. 2026-07-22 14:07 UTCEPSS rescore
  14. 2026-07-22 14:07 UTCEPSS rescore
  15. 2026-07-21 15:24 UTCEPSS rescore
  16. 2026-07-20 17:07 UTCEPSS rescore
  17. 2026-07-19 14:30 UTCEPSS rescore
  18. 2026-07-19 14:30 UTCEPSS rescore
  19. 2026-07-19 02:28 UTCEPSS rescore
  20. 2026-07-19 02:28 UTCEPSS rescore
  21. 2026-07-18 10:04 UTCEPSS rescore
  22. 2026-07-18 10:04 UTCEPSS rescore
  23. 2026-07-16 17:02 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 16:57 UTCEPSS rescore
Show 75 more
  1. 2026-07-15 01:59 UTCEPSS rescore
  2. 2026-07-15 01:59 UTCEPSS rescore
  3. 2026-07-13 22:29 UTCEPSS rescore
  4. 2026-07-13 22:29 UTCEPSS rescore
  5. 2026-07-13 06:12 UTCEPSS rescore
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 08:27 UTCEPSS rescore
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-10 01:47 UTCOSV refresh
  10. 2026-07-09 19:09 UTCEPSS rescore
  11. 2026-07-09 19:09 UTCEPSS rescore
  12. 2026-07-07 13:45 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-04 06:30 UTCEPSS rescore
  18. 2026-07-01 15:06 UTCEPSS rescore
  19. 2026-07-01 15:06 UTCEPSS rescore
  20. 2026-06-30 23:22 UTCEPSS rescore
  21. 2026-06-30 23:22 UTCEPSS rescore
  22. 2026-06-29 14:06 UTCEPSS rescore
  23. 2026-06-29 14:06 UTCEPSS rescore
  24. 2026-06-28 14:07 UTCEPSS rescore
  25. 2026-06-28 14:07 UTCEPSS rescore
  26. 2026-06-28 04:55 UTCEPSS rescore
  27. 2026-06-28 04:55 UTCEPSS rescore
  28. 2026-06-27 03:08 UTCEPSS rescore
  29. 2026-06-27 03:08 UTCEPSS rescore
  30. 2026-06-25 13:49 UTCEPSS rescore
  31. 2026-06-25 13:49 UTCEPSS rescore
  32. 2026-06-24 14:04 UTCEPSS rescore
  33. 2026-06-24 14:04 UTCEPSS rescore
  34. 2026-06-23 21:32 UTCEPSS rescore
  35. 2026-06-23 21:32 UTCEPSS rescore
  36. 2026-06-22 14:25 UTCEPSS rescore
  37. 2026-06-22 14:25 UTCEPSS rescore
  38. 2026-06-21 14:56 UTCEPSS rescore
  39. 2026-06-21 14:56 UTCEPSS rescore
  40. 2026-06-21 12:31 UTCOSV refresh
  41. 2026-06-21 01:59 UTCEPSS rescore
  42. 2026-06-21 01:59 UTCEPSS rescore
  43. 2026-06-19 19:25 UTCEPSS rescore
  44. 2026-06-19 19:25 UTCEPSS rescore
  45. 2026-06-18 17:52 UTCEPSS rescore
  46. 2026-06-18 17:52 UTCEPSS rescore
  47. 2026-06-17 17:52 UTCEPSS rescore
  48. 2026-06-14 23:17 UTCEPSS rescore
  49. 2026-06-13 23:00 UTCEPSS rescore
  50. 2026-06-12 23:11 UTCEPSS rescore
  51. 2026-06-11 14:00 UTCEPSS rescore
  52. 2026-06-10 22:18 UTCEPSS rescore
  53. 2026-06-10 13:22 UTCEPSS rescore
  54. 2026-06-08 14:16 UTCEPSS rescore
  55. 2026-06-08 14:16 UTCEPSS rescore
  56. 2026-06-07 15:24 UTCEPSS rescore
  57. 2026-06-06 13:47 UTCEPSS rescore
  58. 2026-06-06 13:47 UTCEPSS rescore
  59. 2026-06-05 22:46 UTCEPSS rescore
  60. 2026-06-05 22:46 UTCEPSS rescore
  61. 2026-06-05 06:10 UTCEPSS rescore
  62. 2026-06-05 06:10 UTCEPSS rescore
  63. 2026-06-04 13:12 UTCEPSS rescore
  64. 2026-06-04 13:12 UTCEPSS rescore
  65. 2026-06-02 20:12 UTCEPSS rescore
  66. 2026-06-02 05:39 UTCOSV refresh
  67. 2026-06-01 13:51 UTCEPSS rescore
  68. 2026-06-01 13:51 UTCEPSS rescore
  69. 2026-05-31 22:30 UTCEPSS rescore
  70. 2026-05-31 22:30 UTCEPSS rescore
  71. 2026-05-31 00:16 UTCEPSS rescore
  72. 2026-05-29 13:44 UTCEPSS rescore
  73. 2026-05-28 13:44 UTCEPSS rescore
  74. 2026-05-28 13:44 UTCEPSS rescore
  75. 2026-05-28 13:44 UTCEPSS rescore

Frequently asked(5)

What is CVE-2025-40206?
CVE-2025-40206 is a high vulnerability published on November 12, 2025. In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_objref: validate objref and objrefmap expressions Referencing a synproxy stateful object from OUTPUT hook causes kernel crash due to infinite recursive calls: BUG: TASK stack guard page was hit at 000000008bda5b8c…
When was CVE-2025-40206 disclosed?
CVE-2025-40206 was first published in the National Vulnerability Database on November 12, 2025, with the most recent update on July 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-40206 actively exploited?
CVE-2025-40206 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 96.1% of all scored CVEs.
What is the CVSS score of CVE-2025-40206?
CVE-2025-40206 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2025-40206?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-40206, 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

Explore the affected products and dependency analysis for CVE-2025-40206

Explore →

Is Your Infrastructure Affected by CVE-2025-40206?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs