CVE-2026-31665

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-04-24. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
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

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:

netfilter: nft_ct: fix use-after-free in timeout object destroy

nft_ct_timeout_obj_destroy() frees the timeout object with kfree() immediately after nf_ct_untimeout(), without waiting for an RCU grace period. Concurrent packet processing on other CPUs may still hold RCU-protected references to the timeout object obtained via rcu_dereference() in nf_ct_timeout_data().

Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer freeing until after an RCU grace period, matching the approach already used in nfnetlink_cttimeout.c.

KASAN report: BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0 Read of size 4 at addr ffff8881035fe19c by task exploit/80

Call Trace: nf_conntrack_tcp_packet+0x1381/0x29d0 nf_conntrack_in+0x612/0x8b0 nf_hook_slow+0x70/0x100 __ip_local_out+0x1b2/0x210 tcp_sendmsg_locked+0x722/0x1580 __sys_sendto+0x2d8/0x320

Allocated by task 75: nft_ct_timeout_obj_init+0xf6/0x290 nft_obj_init+0x107/0x1b0 nf_tables_newobj+0x680/0x9c0 nfnetlink_rcv_batch+0xc29/0xe00

Freed by task 26: nft_obj_destroy+0x3f/0xa0 nf_tables_trans_destroy_work+0x51c/0x5c0 process_one_work+0x2c4/0x5a0

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
2%
KEV
Not listed

Published

April 24, 2026

Last Modified

August 5, 2026

Advisory Details (8)

Auto-updated Jun 4, 2026
No patch confirmed yet.
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f8dca15a1b190787bbd03285304b569631160eda
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f16fe84879a5280f05ebbcea593a189ba0f3e79a
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d0983b48c10d1509fd795c155f8b1e832e1369ff
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c581e5c8f2b59158f62efe61c1a3dc36189081ff
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c458fc1c278a65ad5381083121d39a479973ebed
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b42aca3660dc2627a29a38131597ca610dc451f9
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/aa7cfa16f98f8ec3e6d47c34e1a8c1ae4b9b8b77
generic

netfilter: nft_ct: fix use-after-free in timeout object destroy - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/070abdf1b04325b21a20a2a0c39a2208af107275

Vendor Advisories for CVE-2026-31665(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
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 (124 versions)6.19.13-1—

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 8× in last 7d / 65× 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 240 total refreshes for this CVE.

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

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

Frequently asked(5)

What is CVE-2026-31665?
CVE-2026-31665 is a high vulnerability published on April 24, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_ct: fix use-after-free in timeout object destroy nftcttimeoutobjdestroy() frees the timeout object with kfree() immediately after nfctuntimeout(), without waiting for an RCU grace period. Concurrent packet processing…
When was CVE-2026-31665 disclosed?
CVE-2026-31665 was first published in the National Vulnerability Database on April 24, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31665 actively exploited?
CVE-2026-31665 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 97.7% of all scored CVEs.
What is the CVSS score of CVE-2026-31665?
CVE-2026-31665 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-31665?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31665, 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-2026-31665

Explore →

Is Your Infrastructure Affected by CVE-2026-31665?

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

Start Free Scan →Browse All CVEs