CVE-2026-43249

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-06. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.8Exploit: 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:

9p/xen: protect xen_9pfs_front_free against concurrent calls

The xenwatch thread can race with other back-end change notifications and call xen_9pfs_front_free() twice, hitting the observed general protection fault due to a double-free. Guard the teardown path so only one caller can release the front-end state at a time, preventing the crash.

This is a fix for the following double-free:

[ 27.052347] Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 27.052357] CPU: 0 UID: 0 PID: 32 Comm: xenwatch Not tainted 6.18.0-02087-g51ab33fc0a8b-dirty #60 PREEMPT(none) [ 27.052363] RIP: e030:xen_9pfs_front_free+0x1d/0x150 [ 27.052368] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 41 55 41 54 55 48 89 fd 48 c7 c7 48 d0 92 85 53 e8 cb cb 05 00 48 8b 45 08 48 8b 55 00 <48> 3b 28 0f 85 f9 28 35 fe 48 3b 6a 08 0f 85 ef 28 35 fe 48 89 42 [ 27.052377] RSP: e02b:ffffc9004016fdd0 EFLAGS: 00010246 [ 27.052381] RAX: 6b6b6b6b6b6b6b6b RBX: ffff88800d66e400 RCX: 0000000000000000 [ 27.052385] RDX: 6b6b6b6b6b6b6b6b RSI: 0000000000000000 RDI: 0000000000000000 [ 27.052389] RBP: ffff88800a887040 R08: 0000000000000000 R09: 0000000000000000 [ 27.052393] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888009e46b68 [ 27.052397] R13: 0000000000000200 R14: 0000000000000000 R15: ffff88800a887040 [ 27.052404] FS: 0000000000000000(0000) GS:ffff88808ca57000(0000) knlGS:0000000000000000 [ 27.052408] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.052412] CR2: 00007f9714004360 CR3: 0000000004834000 CR4: 0000000000050660 [ 27.052418] Call Trace: [ 27.052420] [ 27.052422] xen_9pfs_front_changed+0x5d5/0x720 [ 27.052426] ? xenbus_otherend_changed+0x72/0x140 [ 27.052430] ? __pfx_xenwatch_thread+0x10/0x10 [ 27.052434] xenwatch_thread+0x94/0x1c0 [ 27.052438] ? __pfx_autoremove_wake_function+0x10/0x10 [ 27.052442] kthread+0xf8/0x240 [ 27.052445] ? __pfx_kthread+0x10/0x10 [ 27.052449] ? __pfx_kthread+0x10/0x10 [ 27.052452] ret_from_fork+0x16b/0x1a0 [ 27.052456] ? __pfx_kthread+0x10/0x10 [ 27.052459] ret_from_fork_asm+0x1a/0x30 [ 27.052463] [ 27.052465] Modules linked in: [ 27.052471] ---[ end trace 0000000000000000 ]---

CVSS v3
8.8
EG Score
8.8(medium)
EPSS
15.2%
KEV
Not listed

Published

May 6, 2026

Last Modified

May 11, 2026

Advisory Details (4)

Auto-updated May 11, 2026
No patch confirmed yet.
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ce8ded2e61f47747e31eeefb44dc24a2160a7e32
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bf841d43f7a33d75675ba7f4e214ac1c67913065
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a5d00dff97118a32fcf5fec7a4c3f864c4620c4e
generic

9p/xen: protect xen_9pfs_front_free against concurrent calls - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/59e7707492576bdbfa8c1dbe7d90791df31e4773

Vendor Advisories for CVE-2026-43249(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-43249?
CVE-2026-43249 is a high vulnerability published on May 6, 2026. In the Linux kernel, the following vulnerability has been resolved: 9p/xen: protect xen9pfsfront_free against concurrent calls The xenwatch thread can race with other back-end change notifications and call xen9pfsfront_free() twice, hitting the observed general protection fault due to a…
When was CVE-2026-43249 disclosed?
CVE-2026-43249 was first published in the National Vulnerability Database on May 6, 2026, with the most recent update on May 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43249 actively exploited?
CVE-2026-43249 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 15.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-43249?
CVE-2026-43249 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-43249?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43249, 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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