CVE-2026-31664

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-04-24. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: 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:

xfrm: clear trailing padding in build_polexpire()

build_expire() clears the trailing padding bytes of struct xfrm_user_expire after setting the hard field via memset_after(), but the analogous function build_polexpire() does not do this for struct xfrm_user_polexpire.

The padding bytes after the __u8 hard field are left uninitialized from the heap allocation, and are then sent to userspace via netlink multicast to XFRMNLGRP_EXPIRE listeners, leaking kernel heap memory contents.

Add the missing memset_after() call, matching build_expire().

CVSS v3
5.5
EG Score
5.5(medium)
EPSS
2.2%
KEV
Not listed

Published

April 24, 2026

Last Modified

July 14, 2026

References (10)

Vendor Advisories for CVE-2026-31664(2)

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 12× in last 7d / 44× 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 132 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. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  6. 2026-07-14 13:11 UTCMITRE cvelistV5
  7. 2026-07-13 22:30 UTCEPSS rescore
  8. 2026-07-13 06:13 UTCEPSS rescore
  9. 2026-07-13 06:13 UTCEPSS rescore
  10. 2026-07-12 05:46 UTCEPSS rescore
  11. 2026-07-11 08:27 UTCEPSS rescore
  12. 2026-07-09 19:10 UTCEPSS rescore
  13. 2026-07-08 15:15 UTCEPSS rescore
  14. 2026-07-07 13:46 UTCEPSS rescore
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 16:27 UTCEPSS rescore
  17. 2026-07-06 02:23 UTCEPSS rescore
  18. 2026-07-06 02:23 UTCEPSS rescore
  19. 2026-07-05 02:30 UTCEPSS rescore
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-01 15:06 UTCEPSS rescore
  22. 2026-06-30 23:22 UTCEPSS rescore
  23. 2026-06-29 14:06 UTCEPSS rescore
  24. 2026-06-29 14:06 UTCEPSS rescore
  25. 2026-06-28 14:07 UTCEPSS rescore
Show 75 more
  1. 2026-06-28 14:07 UTCEPSS rescore
  2. 2026-06-28 04:56 UTCEPSS rescore
  3. 2026-06-28 04:56 UTCEPSS rescore
  4. 2026-06-27 03:08 UTCEPSS rescore
  5. 2026-06-25 13:49 UTCEPSS rescore
  6. 2026-06-25 13:49 UTCEPSS rescore
  7. 2026-06-24 14:05 UTCEPSS rescore
  8. 2026-06-23 21:33 UTCEPSS rescore
  9. 2026-06-23 21:33 UTCEPSS rescore
  10. 2026-06-22 14:25 UTCEPSS rescore
  11. 2026-06-22 14:25 UTCEPSS rescore
  12. 2026-06-21 14:56 UTCEPSS rescore
  13. 2026-06-21 14:56 UTCEPSS rescore
  14. 2026-06-21 01:59 UTCEPSS rescore
  15. 2026-06-19 19:25 UTCEPSS rescore
  16. 2026-06-19 19:25 UTCEPSS rescore
  17. 2026-06-18 17:52 UTCEPSS rescore
  18. 2026-06-18 17:52 UTCEPSS rescore
  19. 2026-06-16 17:52 UTCEPSS rescore
  20. 2026-06-15 17:49 UTCEPSS rescore
  21. 2026-06-14 23:18 UTCEPSS rescore
  22. 2026-06-14 11:47 UTCEG score recompute
  23. 2026-06-14 11:47 UTCVendor advisory
  24. 2026-06-14 11:47 UTCGHSA enrichment
  25. 2026-06-13 23:00 UTCEPSS rescore
  26. 2026-06-12 23:12 UTCEPSS rescore
  27. 2026-06-12 23:12 UTCEPSS rescore
  28. 2026-06-11 14:00 UTCEPSS rescore
  29. 2026-06-11 13:39 UTCEG score recompute
  30. 2026-06-11 13:39 UTCVendor advisory
  31. 2026-06-11 13:39 UTCGHSA enrichment
  32. 2026-06-10 22:18 UTCEPSS rescore
  33. 2026-06-10 13:22 UTCEPSS rescore
  34. 2026-06-10 05:27 UTCEG score recompute
  35. 2026-06-10 05:27 UTCVendor advisory
  36. 2026-06-10 05:27 UTCGHSA enrichment
  37. 2026-06-09 03:26 UTCEG score recompute
  38. 2026-06-09 03:26 UTCVendor advisory
  39. 2026-06-09 03:26 UTCGHSA enrichment
  40. 2026-06-08 14:17 UTCEPSS rescore
  41. 2026-06-08 14:17 UTCEPSS rescore
  42. 2026-06-08 01:25 UTCEG score recompute
  43. 2026-06-08 01:25 UTCVendor advisory
  44. 2026-06-08 01:25 UTCGHSA enrichment
  45. 2026-06-07 15:25 UTCEPSS rescore
  46. 2026-06-07 15:25 UTCEPSS rescore
  47. 2026-06-07 15:25 UTCEPSS rescore
  48. 2026-06-06 23:24 UTCEG score recompute
  49. 2026-06-06 23:24 UTCVendor advisory
  50. 2026-06-06 23:24 UTCGHSA enrichment
  51. 2026-06-06 13:47 UTCEPSS rescore
  52. 2026-06-06 13:47 UTCEPSS rescore
  53. 2026-06-05 22:47 UTCEPSS rescore
  54. 2026-06-05 22:47 UTCEPSS rescore
  55. 2026-06-05 21:22 UTCEG score recompute
  56. 2026-06-05 21:22 UTCVendor advisory
  57. 2026-06-05 21:22 UTCGHSA enrichment
  58. 2026-06-05 06:10 UTCEPSS rescore
  59. 2026-06-05 06:10 UTCEPSS rescore
  60. 2026-06-04 19:21 UTCEG score recompute
  61. 2026-06-04 19:21 UTCVendor advisory
  62. 2026-06-04 19:21 UTCGHSA enrichment
  63. 2026-06-04 13:12 UTCEPSS rescore
  64. 2026-06-04 13:12 UTCEPSS rescore
  65. 2026-06-03 17:20 UTCEG score recompute
  66. 2026-06-03 17:20 UTCVendor advisory
  67. 2026-06-03 17:20 UTCGHSA enrichment
  68. 2026-06-02 20:13 UTCEPSS rescore
  69. 2026-06-02 20:13 UTCEPSS rescore
  70. 2026-06-02 15:18 UTCEG score recompute
  71. 2026-06-02 15:18 UTCVendor advisory
  72. 2026-06-02 15:18 UTCGHSA enrichment
  73. 2026-06-01 13:51 UTCEPSS rescore
  74. 2026-06-01 13:51 UTCEPSS rescore
  75. 2026-06-01 13:17 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-31664?
CVE-2026-31664 is a medium vulnerability published on April 24, 2026. In the Linux kernel, the following vulnerability has been resolved: xfrm: clear trailing padding in build_polexpire() build_expire() clears the trailing padding bytes of struct xfrmuserexpire after setting the hard field via memset_after(), but the analogous function build_polexpire() does not do…
When was CVE-2026-31664 disclosed?
CVE-2026-31664 was first published in the National Vulnerability Database on April 24, 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-2026-31664 actively exploited?
CVE-2026-31664 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-31664?
CVE-2026-31664 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-31664?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31664, 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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