CVE-2026-31668

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-04-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 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:

seg6: separate dst_cache for input and output paths in seg6 lwtunnel

The seg6 lwtunnel uses a single dst_cache per encap route, shared between seg6_input_core() and seg6_output_core(). These two paths can perform the post-encap SID lookup in different routing contexts (e.g., ip rules matching on the ingress interface, or VRF table separation). Whichever path runs first populates the cache, and the other reuses it blindly, bypassing its own lookup.

Fix this by splitting the cache into cache_input and cache_output, so each path maintains its own cached dst independently.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
35.8%
KEV
Not listed

Published

April 24, 2026

Last Modified

April 27, 2026

Advisory Details (8)

Auto-updated May 10, 2026
No patch confirmed yet.
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fb56de5d99218de49d5d43ef3a99e062ecd0f9a1
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c3812651b522fe8437ebb7063b75ddb95b571643
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/84d458018b147176b259347103fccb7e93abd2b1
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/750569d6987a0ff46317a4b86eb3907e296287bf
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6305ad032b03d2ea4181b953a66e19a9a6ed053c
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/57d0374d14fa667dec6952173b93e7e84486d5c9
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1dec91d3b1cefb82635761b7812154af3ef46449
generic

seg6: separate dst_cache for input and output paths in seg6 lwtunnel - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a

Vendor Advisories for CVE-2026-31668(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 43× 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 310 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-31668?
CVE-2026-31668 is a critical vulnerability published on April 24, 2026. In the Linux kernel, the following vulnerability has been resolved: seg6: separate dst_cache for input and output paths in seg6 lwtunnel The seg6 lwtunnel uses a single dst_cache per encap route, shared between seg6inputcore() and seg6outputcore(). These two paths can perform the post-encap SID…
When was CVE-2026-31668 disclosed?
CVE-2026-31668 was first published in the National Vulnerability Database on April 24, 2026, with the most recent update on April 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31668 actively exploited?
CVE-2026-31668 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 35.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-31668?
CVE-2026-31668 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-31668?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31668, 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.

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